To cool 250 mL of coffee at 90.0°C, you put a 80 g metal spoon cooled to 0.0°C in the coffee. After thermal equilibrium has been reached, what is the final temperature of your coffee? Assume energy is exchanged only between the spoon and the coffee. The specific heat capacity of the metal spoon is 0.80 J/(g°C). Assume the specific heat and density of coffee are the same as those of water, 4.18 J/(g · °C) and 1.00 g/mL. Keep one decimal in your answer.
Answer:
The correct answer is 84.81 °C.
Explanation:
Based on the given information, the volume or mass of coffee is 250 ml, and the mass of metal spoon is 80 grams. The specific heat capacity of metal spoon is 0.80 J/g °C, and the specific heat capacity of coffee is 4.18 J/g °C. In the given case, heat is lost from the coffee and is gained by the spoon.
For finding the final temperature of the coffee, the formula to be used is Q = msΔT, here m is the mass, s is the specific heat, and ΔT is the change in temperature.
Heat lost from the coffee = Heat gained by the spoon
250 × 4.18 (90 - T2) = 80 × 0.8 (T2 - 0)
1045 (90 - T2) = 64 (T2 -0)
94050 - 1045 T2 = 64 T2
94050 = 1045 T2 + 64 T2
94050 = 1109 T2
T2 = 84.84 °C
Write a chemical equation for the reaction that occurs in the following cell: Cu|Cu2+(aq)||Ag+(aq)|Ag. Of the two metals, copper and silver, which is the anode and which is the cathode?
Answer:
Explanation:
We are to write a chemical equation for the reaction that occurs in the following cell: Cu|Cu2+(aq)||Ag+(aq)|Ag.
And to determine which one of the two metals, (copper and silver) is the anode and which is the cathode?
The chemical equation for the reaction is as follows:
[tex]\mathbf{Cu + 2Ag^+ \to Cu^{2+}+2Ag}[/tex]
The atoms of the Copper electrodes undergo oxidation and loses two electrons each to form copper II ions [tex](Cu^{2+})[/tex] which go into the solution. The copper then becomes negatively charged and functions as the negative electrode i.e the anode
The oxidation half reaction is:
[tex]\mathsf{Cu \to Cu^{2+} + 2e^-}[/tex]
The silver ions [tex]Ag^+[/tex] becomes reduced by gaining two electrons each from the metallic copper which was deposited into the silver electrode. The silver electrode thus becomes positively charged and functions as the positive electrode. i.e the cathode.
The reduction half reaction is:
[tex]\mathtt{Ag^+ + 1 e^- \to Ag}[/tex]
What kind of intermolecular forces act between a chloramine NH2Cl molecule and a water molecule?
Note: If there is more than one type of intermolecular force that acts, be sure to list them all, with a comma between the name of each force.
Answer:
Dispersion forcesHydrogen bondingDipole-dipole forceExplanation:
Dispersion force is caused by weak Van der Waals attraction between molecules.
Because chloroamine and water are both polar solvents, dipole-dipole force of attraction exists between them. There is also hydrogen bonding present from the water molecules.
Answer: The forces present include;
1. Hydrogen bonding
2. Dispersion bonding
3. Dipole to Dipole bonding.
Explanation:
1. Hydrogen bonding is an electrostatic force that occur between atoms of hydrogen which is covalently bonded to electronegative atoms.
2. Dispersion force is type of force that occur between molecules which is caused by weak Van der Waals attraction between molecules.
3. Dipole -Dipole force occur when atoms with partial charges within a molecule attract themselves with another opposite opposite partial charge that is around the molecule.
Therefore,
Because chloroamine and water are both polar solvents, hydrogen bond, dispersion force and dipole-dipole force of attration occur between them. The hydrogen bonding occur between the water molecules.
What happens to the flame of a Bunsen burner when there is an adequate supply of oxygen available to react with the fuel
Answer:
The answer to your question is given below.
Explanation:
When there is an adequate supply of oxygen available to react with the fuel of a bunsen burner, the flame produce is a non luminous bunsen flame.
This flame i.e non luminous flame produced is much hotter than the luminous and three zones can be seen in the flame. This zones are
1. The zone of unburnt gas.
2. The luminous zone.
3. The outermost non luminous zone.
When an adequate supply of oxygen is available to react with the fuel of a Bunsen burner, there is complete combustion of the fuel and a non-luminous flame is produced.
Complete combustion occurs where there is plentiful supply of oxygen. During the reaction, more heat energy is produced as the flame is non-luminous and less soot is produced.
A non-luminous flame is a flame which produces less light but more heat energy. It is usually blue in color and consists of three zones. These zones are:
1. The zone of unburnt gas.
2. The luminous zone.
3. The outermost non luminous zone.
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Consider the following reaction at 298K.
2 H+(aq) + 2 Cr2+(aq) =H2(g) + 2 Cr3+(aq)
Which of the following statements are correct?
a) K > 1
b) ΔGo < 0
c) Eocell < 0
d) n = 2 mol electrons
The question is incomplete, the complete question is;
Consider the following reaction at 298K.
2 H+(aq) + 2 Cr2+(aq) =H2(g) + 2 Cr3+(aq)
Which of the following statements are correct?
Choose all that apply.
K > 1
ΔGo < 0
Eocell < 0
n = 2 mol electrons
The reaction is reactant-favored.
Answer:
K > 1
ΔGo < 0
n = 2 mol electrons
Explanation:
If we look at the reaction; 2 H+(aq) + 2 Cr2+(aq) -----> H2(g) + 2 Cr3+(aq), we will notice that the reaction is a spontaneous reaction because E°cell= 0-(-0.41) = 0.41 V
If the reaction is a spontaneous electrochemical process, we expect it to be product favoured with K>1. Also, a spontaneous reaction must have ∆G<0.
Lastly, we can see that two electrons were transferred according to the balanced equation for the electrochemical reaction.
According to the following reaction, how many moles of dichloromethane (CH2Cl2) will be formed upon the complete reaction of 0.766 moles methane (CH4) with excess carbon tetrachloride?
methane (CH4) (g) + carbon tetrachloride (g) → dichloromethane (CH2Cl2) (g)
Answer:
[tex]1.53~moles~CH_2Cl_2[/tex].
Explanation:
We can start with the reaction, if we know the formula for each compound:
-) Methane: [tex]CH_4[/tex]
-) Carbon tetrachloride: [tex]CCl_4[/tex]
-) Dichloromethane: [tex]CH_2Cl_2[/tex]
With this in mind, we can write the reaction:
[tex]CH_4~+~CCl_4~->~CH_2Cl_2[/tex]
Now, we can balance the reaction:
[tex]CH_4~+~CCl_4~->~2CH_2Cl_2[/tex]
After this, we have 2 carbon atoms on each side, 4 hydrogen atom on each side, and 4 chlorine atoms on each side.
If we want to know how many moles of [tex]CH_2Cl_2[/tex] would be produced with .766 moles of [tex]CH_4[/tex], we have to check the balanced reaction and use the molar ratio. In this case, the molar ratio is 1 mol [tex]CH_4[/tex] will produce 2 moles of [tex]CH_2Cl_2[/tex] (1:2). So:
[tex]0.766~moles~CH_4\frac{2~moles~CH_2Cl_2}{1~mol~CH_4}=1.53~moles~CH_2Cl_2[/tex]
We wil have [tex]1.53~moles~CH_2Cl_2[/tex].
I hope it helps!
This graduated cylinder is being used to measure an amount of a liquid. The numbers represent milliliters. What is the most precise measurement of the volume of this liquid? 37.0 ml 37.1 ml 37.2 ml 37.3 ml
Answer:
37.1 mL
Explanation:
To accurately read the measurement using a cylinder, we read the measurement at the meniscus i.e measurement under the curve as shown in the diagram above.
The meniscus i.e the measurement under the curve as shown above is 37.1 mL.
Therefore, the volume of the liquid as obtained from the cylinder is 37.1 mL
Answer:
37.1 ml
Explanation:
a graduated cylinder's measurement is taken at the bottom of the meniscus
8. An unknown mixture that is uniform, does show the Tyndall Effect, and does
not have any particles settling out is a... *
solution
colloid
suspension
pure substance
Answer:
B. Colloid
Explanation:
Colloid is a mixture that is made up of very small homogeneous particles, thus can not be separated into fractions. Its particles do not settle as other solution, but are evenly dispersed in the medium. Some examples are: liquid milk, jelly, rubber etc
Since colloid is a solution, thus it is made up of two parts; its particles and dispersing medium.
what is point group of allene?
Allene (1,2-propadiene) has point group D2d, itself is achiral because it has two planes of symmetry. ... An allene with substituents on one terminal carbon atom are unlike and substituent on other terminal carbon atoms are same, allene will be achiral. It will have one symmetry plane.
Hope this helped :)
Which of the following substances has the strongest intermolecular forces?
a. HCl
b. C8H18
c. CH3OH
d. CH4
e. CO2
Answer:
HCl.
Explanation:
Of all the type of bond, Ionic bonds are the strongest. Among all the compounds in the options only HCl has ionic bond, rest have covalent bonds. So, the strongest intermolecular forces is in HCl. Ionic bond are formed with the transfer of electrons, one atom is donor and the other is acceptor.
Calculate the mole fraction of KI in a solution made by dissolving 3.4 g of KI in 5.8 g of water. (Step by step)
A. 0.060
B. 0.064
C. 0.37
D. 0.59
E. 6.4
Answer:
The correct answer is 0.058
Step-by-step explanation:
The mole fraction of KI (X) in the solution is the number of moles of KI divided into the total number of moles of the solution (nt):
X= moles KI/nt
First we have to calculate the molecular weights of the components of the solution: KI and water (H₂O):
Molecular weight (Mw) of KI:
Mw(KI)= 39 g/mol + 127 g/mol = 166 g/mol
Molecular weight of H₂O:
Mw(H₂O)= (1 g/mol x 2) + 16 g/mol = 18 g/mol
Then, we calculate the number of moles there is of each component in the solution by dividing the mass into Mw:
Moles of KI= mass KI/Mw(KI) = 3.4 g/166 g/mol = 0.020 mol KI
Moles of H₂O= mass H₂O/Mw(H₂O)= 5.8 g/18 g/mol = 0.322 mol H₂O
Thus, the total moles of solution will be:
nt= moles KI + moles H₂O= 0.020 mol + 0.322 mol = 0.342 mol
Finally, we divide the moles of KI into the total moles of solution (nt) to obtain the mole fraction (X):
X= moles KI/nt = 0.020 mol/0.342 mol = 0.058
How many moles of UF6 would have to be decomposed to provide enough fluorine to prepare 8.99 mol of CF4? (Assume sufficient carbon is available).
Answer:
5.99 moles of [tex]UF_6[/tex]
Explanation:
In this case, we can start with the decomposition of [tex]UF_6[/tex], so:
[tex]UF_6~->~U~+~3F_2[/tex] (Reaction 1)
The [tex]F_2[/tex] can react with carbon to produce [tex]CF_4[/tex]:
[tex]CF_4~+~2F_2~->~CF_4[/tex] (Reaction 2)
If we 8.99 mol of [tex]CF_4[/tex], we can calculate the moles of [tex]F_2[/tex] that we need. In reaction 2 we have a molar ratio of 1:2 (2 moles of [tex]F_2[/tex] will produce 1 mol of [tex]CF_4[/tex]):
[tex]8.99~mol~CF_4\frac{2~mol~F_2}{1~mol~CF_4}~=~17.98~mol~F_2[/tex]
With this value and using the molar ratio in reaction 1 (3 moles of [tex]F_2[/tex] are producing by each mol of [tex]UF_6[/tex]), so:
[tex]17.98~mol~F_2\frac{1~mol~UF_6}{3~mol~F_2}~=~5.99~mol~UF_6[/tex]
So, we will need 5.99 moles of [tex]UF_6[/tex] to produce 8.99 mol of [tex]CF_4[/tex].
I hope it helps!
When you're deciding what to eat, you may want to consider the environmental impact of your meal. Rank these four foods according to the amount of resources (land or grain) required to produce 1kg of each.
1. Egg
2. Chicken
3. Pork
4. Beef
A. Least resources required
B. Most resources required
Answer:
From the most resources to the least, it is 3, 4, 2, 1.
Explanation:
Pork is a large animal but not as much as a cow but it also does not produce as much meat as a cow. In terms of land required and total meat produced, pork is the highest on this list so it is option B.
The most amount of land and resources are taken up by cows, but they also produce a lot more meat than porks so they are in the second place on this list.
Chickens require a small amount of space but produce little meat.
If we guess that each egg weighs 60 grams, 1 kg of eggs equals to almost 17 eggs which a single chicken can produce easily. So the eggs require the least resources which means that they are option A.
I hope this answer helps.
What is the pH of a solution made by mixing 30.00 mL 0.10 M HCl with 40.00 mL of 0.10 M KOH? Assume that the volumes of the solutions are additive.
Answer:
pH = 12.15
Explanation:
To determine the pH of the HCl and KOH mixture, we need to know that the reaction is a neutralization type.
HCl + KOH → H₂O + KCl
We need to determine the moles of each compound
M = mmol / V (mL) → 30 mL . 0.10 M = 3 mmoles of HCl
M = mmol / V (mL) → 40 mL . 0.10 M = 4 mmoles of KOH
The base is in excess, so the HCl will completely react and we would produce the same mmoles of KCl
HCl + KOH → H₂O + KCl
3 m 4 m -
1 m 3 m
As the KCl is a neutral salt, it does not have any effect on the pH, so the pH will be affected, by the strong base.
1 mmol of KOH has 1 mmol of OH⁻, so the [OH⁻] will be 1 mmol / Tot volume
[OH⁻] 1 mmol / 70 mL = 0.014285 M
- log [OH⁻] = 1.85 → pH = 14 - pOH → 14 - 1.85 = 12.15
The pH of the solution is 12.15.
Calculation of the pH of the solution:The following equation should be
HCl + KOH → H₂O + KCl
Here we have to measured the moles of each compound i.e.
M = mmol / V (mL) → 30 mL . 0.10 M = 3 mmoles of HCl
M = mmol / V (mL) → 40 mL . 0.10 M = 4 mmoles of KOH
So, it be like
3 m 4 m -
1 m 3 m
Now the pH should be like
= [OH⁻] 1 mmol / 70 mL
= 0.014285 M
Now
= - log [OH⁻] = 1.85
pH = 14 - pOH
= 14 - 1.85
= 12.15
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taxes you pay to the federal government are: A.federal taxes B.import taxes C.state taxes D.export taxes
Answer:
A federal taxes
Explanation:
because these are taxes paid to the federal government of a state
Answer:
Hey there!
As the name suggests, you pay Federal Taxes to the government.
Let me know if this helps :)
Nurse Antonio measured out 7 grams of sodium chloride (NaCI). Using dimensional analysis, calculate how many moles of NaCI he weighed out.
Answer:
0.119 moles
Explanation:
Given that,
Mass measured by Nurse Antonio is 7 grams of NaCl
To find,
The no of moles of NaCl
Solution,
The number of moles is given by
[tex]n=\dfrac{m}{M}[/tex]
m is given mass
M is molar mass
For NaCl, molar mass is 23+35.5 = 58.5 grams
So,
[tex]n=\dfrac{7}{58.5}\\\\n=0.119\ \text{moles}[/tex]
Therefore, there are 0.119 moles of NaCl.
A pool is 34.0 m long and 31.0 m wide. How many mL of water are needed to fill the pool to an average depth of 4.98 ft? Enter your answer in scientific notation.
____x10___mL
Answer:
Amount of water in mL = 1.75⁹ × 10 ml (Approx)
Explanation:
Given:
Length of pool = 34 m
Width of pool = 31 m
Height of pool = 4.98 ft
Find:
Amount of water in mL
Computation:
1 ft = 0.3048 m
Height of pool = 4.98 (0.3048)
Height of pool = 1.5179 m
Volume of pool = (34)(31)(1.5179)
Volume of pool = 1,754.70 m³
1 m³ = 10⁶ ml
Amount of water in mL = 1,754.70 × 10⁶ ml
Amount of water in mL = 1.75⁹ × 10 ml (Approx)
Vegetable oil has a specific heat of 1.67/* Calculate the heat required (in kilojoules) to raise the temperature of 500 g of
vegetable oil from room temp (20.0°C) to 150.0°C
Answer:
[tex]Q=108.55kJ[/tex]
Explanation:
Hello,
In this case, we can compute the required heat by using the following equation:
[tex]Q=mCp(T_2-T_1)[/tex]
Thus, by considering the given mass, specific heat and both initial and final temperature, we obtain:
[tex]Q=500g*1.67\frac{J}{g\°C} *(150.0\°C-20.0\°C)*\frac{1kJ}{1000J} \\\\Q=108.55kJ[/tex]
Regards.
A liquid boils when its:_________
a. Temperature is equal to 273 K (standard temperature).
b. Vapor pressure is equal to, or greater than, the external pressure pushing on it.
c. Temperature is greater than room temperature.
d. Vapor pressure is exactly 1 atmosphere.
Answer:
option a. Temperature is equal to 273 k. Is the correct one
A boils when its vapour pressure is equal to, or greater than, the external pressure pushing on it. Therefore, option (b) is correct.
What is the boiling point?A boiling point of a liquid can be defined as the temperature at which the vapour pressure becomes equal to the atmospheric pressure of the liquid. The liquid is converted into a vapour at this temperature.
With the addition of heat that the liquid changes into vapour without any increase in temperature. The vapour pressure increases until it is equal to the pressure of the gas surrounding it as a liquid is heated. Bubbles of vaporized liquid are formed within the liquid and rise to the surface.
At the boiling temperature, the vapour inside the bubble will exert enough pressure to prevent the bubble from collapsing. The molecules of a liquid will able to overcome the forces of attraction between molecules to create vapour.
Therefore, at boiling point, the vapour pressure is equal to, or greater than, the external pressure pushing on it.
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how many significants are in 54.0047
Answer:
There are 6
Explanation:
The significant figures in that number are 5 4 0 0 4 7
Hope this helps:)
Balance this reaction ch3oh+02 c02 h20
Answer:
2CH3OH + 3O2 --> 2CO2 + 4H2O
This is called Combustion of Methanol
Explanation:
Count the numbers of atoms on each sides and try to get the same amount of quantity on each sides, so you'll eventually get "balanced".
or
Watch this video: "How to Balance CH3OH + O2 = CO2+ H2O (Combustion of Methanol)"
Good luck with future work! Keep studying chemistry!
- D
Which of the following reactions should have the larger emf under standard conditions? Why?
CuSO4(aq)+Pb(s) ⇌ PbSO4(s)+Cu(s)
Cu(NO3)2(aq)+Pb(s) ⇌ Pb(NO3)2(aq)+Cu(s)
Answer:
Cu(NO3)2(aq)+Pb(s) ⇌ Pb(NO3)2(aq)+Cu(s)
Explanation:
If we look at the both reactions closely, we will quickly discover that the reaction CuSO4(aq)+Pb(s) ⇌ PbSO4(s)+Cu(s) involves PbSO4.
The compound PbSO4 is insoluble in water and sinks to the bottom of the reaction vessel. When this occurs, the concentration of Pb^2+ becomes low. This will bring about a low voltage in the cell.
On the other hand, Pb(NO3)2 is soluble in water hence the cell voltage in this case is higher than the former.
In the case when we look at both reactions so here we discovered that the reaction of
CuSO4(aq)+Pb(s) ⇌ PbSO4(s)+Cu(s) includes PbSO4.
The compound PbSO4 should be insoluble in water and sinks to the bottom of the reaction vessel. At the time When this occurs, the concentration of Pb^2+ becomes low. This will bring about a low voltage in the cell.
On the other hand, Pb(NO3)2 is soluble in water so the cell voltage in this case is more than the former.
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pleaaaaaaaaaaaaaaaase answerrrrrrr quickkkkkkkkkkk am scared can somebody write me a small kinda article about fractional distillation that could consist of points and paragraph both
Answer:
Hey!I think I can help....
Simple Distillation cannot be used to separate a mixture of two or more miscible liquids Fractional Distillation is used to separate such a mixture into its component parts or fractions. The fractions distil over in ascending order of their boiling points,starting with the fraction with the lowest boiling points. For efficient fractional distillation,the difference in the boiling points between successive fractions must be more than 10°C.In the laboratory,the apparatus for fractional distillation is same as the apparatus for simple distillation, except that a fractioning column is introduced between the distillation flask and the condenser.The fractionating column is packed with glass beads,and does the actual separation. The upper part of the column is at a lower temperature than the lower part .Only the vapour with the same temperature as the upper part of the fractionating column passes on the condenser.(This is the fraction with the lowest boiling point)Vapours with higher boiling points condense as they enter the upper part of the fractionating column and the flow back into the distillation flask.This process is repeated until the fraction with the lowest boiling point is distilled over completely. Then,the temperature in the upper part of yhe column rises until the boiling point of the next fraction is reached. This fraction then starts distilling over.The fractional distillation process continues until Al the component fractions in the mixture distil over.Crude oil or petroleum contains many important natural products such as petrol,kerosene,diesel, heavey oil,natural gases and bitumen.Each of these products can be recovered in its pure form by fractional distillation. The fractional distillation plant is made up of two maim parts----boiler,where the crude oil is kept boiling, and the fractionating tower,where yhe actual separation takes place.The fractions with the lower boiling points will emerge near the top part of the tower while those with higher boiling points will come out near the lower part of the tower..... Thank you for the question, I hope it helps you...Thank you.
A certain solution has a molarity of M = 3.14 mol/L and has a volume of V = 0.760 L . What is the value of n? Express your answer numerically in moles.
Answer:
Thinking...
o-O
(ﾉ◕ヮ◕)ﾉ*:･ﾟ✧
Which method did Dalton use to develop his atomic theory?
He changed atoms of one element into atoms of a different element.
He split individual atoms to identify the particles inside them.
He searched for natural materials that did not contain atoms.
He studied the way in which elements combined during chemical reactions.
Answer:
He studied the way in which the elements combined during chemical reactions
Explanation:
Which method did Dalton use to develop his atomic theory?
D.) He studied the way in which elements combined during chemical reactions.
Answer: It’s D
Explanation:
What electron configuration repreents the first excited state of phosphorus?
A. 1s2 2s2 2p6 3s2 3p2 4s1
B. 1s2 2s2 2p6 3s2 3p4
C. 1s2 2s2 2p6 3s1 3p4
D. 1s2 2s2 2p6 3s2 3p3 4s1
E. 1s2 2s2 2p6 3s2 3p3
Answer:
Option C:
1s2 2s2 2p6 3s1 3p4
Explanation:
At a ground level, Phosphorous has an electronic configuration of 1s2 2s2 2p6 3s2 3p3 (using the spdf notation).
Once the atom becomes excited, an electron from the 3s sub-level will gain energy and jump over to the 3p sub-level, making the configuration 1s2 2s2 2p6 3s1 3p4.
The number of electrons at the 3p sub-level will now become 4 because of the addition of the new electron while the number of atoms at the 3S sub-level will reduce to 1 because an electron left this sub-level.
An aerosol is a colloidal _____ suspended in a _____. A.liquid B.solid C.gas
Answer:
An aerosol is a colloidal A. liquid suspended in a C. gas.
Explanation:
Hence an aerosol is a colloidal solid or liquid suspended in a gas Smoke or fog, for example.
define aerosol?Aerosol is a system of equally dispersed, finely divided liquid or solid particles passing through a gas, often air. Dust and other aerosol particles, which serve as the nuclei for condensation and freezing, are crucial to the precipitation process.
Which two forms of aerosols exist?Secondary aerosols develop when gas is converted into a particle, whereas primary aerosols are made up of particles that are added directly to the gas. Key aerosol categories include sulfates, organic carbon, black carbon, nitrates, mineral dust, and sea salt. These substances typically clump together to create complicated mixtures.
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What is a Spontaneous charge
This means a release of free energy from the system corresponds to a negative change in free energy, but to a positive change for the surroundings.
A family pool holds 10,000.0 gallons of water. How many cubic meters is this?
264.2 gal = 1.0 cubic meter
Answer:
Hey there!
10000 gallons would be 37.85 cubic meters.
Let me know if this helps :)
Answer: 37.8501 m³
Explanation:
10000.0 gal × 1 m³/264.2 gal
=37.8501 m³ (significant digits)
Which of the following is considered a form of technology?
Select one:
a. A line of thought used to explain logically what happened in an experiment.
b. A beaker used in an experiment.
C. A series of procedures followed in an experiment.
d. The ethical practice of considering human and animal rights in research studies.
Answer:
B. a beaker used in an experiment
Explanation: