Answer:
D.
Explanation:
Because if an object is more dense than water it will sink.
A 4.534 g sample of a solid mixture was analyzed for barium ion. First the rock was crushed in a mortar and pestle. 100% of the sample was transferred to a beaker, where it was dissolved in 150.0 mL of d.i. water. to give 152 mL of solution. The aqueous sample was then analyzed by adding a small excess of sulfuric acid. The resultant reaction produced a precipitate of barium sulfate, which was collected by filtration, rinsed, dried and weighed. If 0.5376 g of barium sulfate was obtained, what was the mass percent of barium in the original sample? What was the molar concentration barium in the 152 mL of solution prior to adding sulfuric acid? Show work clearly; include a balanced net ionic chemical equation, units and sig. figs.
Answer:
6.976%
0.0152 M
Explanation:
Step 1: Write the balanced chemical equation
Ba²⁺(aq) + H₂SO₄(aq) ⇒ BaSO₄(s) + 2 H⁺(aq)
The balanced net ionic chemical equation is:
Ba²⁺(aq) + SO₄²⁻(aq) ⇒ BaSO₄(s)
Step 2: Calculate the moles corresponding to 0.5376 g of BaSO₄
The molar mass of BaSO₄ is 233.39 g/mol.
0.5376 g × (1 mol/233.39 g) = 2.303 × 10⁻³ mol
Step 3: Calculate the moles of Ba²⁺ that produced 2.303 × 10⁻³ moles of BaSO₄
The molar ratio of Ba²⁺ to BaSO₄ is 1:1. The moles of Ba²⁺ are 1/1 × 2.303 × 10⁻³ mol = 2.303 × 10⁻³ mol.
Step 4: Calculate the mass corresponding to 2.303 × 10⁻³ moles of Ba²⁺
The molar mass of Ba²⁺ is 137.33 g/mol.
2.303 × 10⁻³ mol × 137.33 g/mol = 0.3163 g
Step 5: Calculate the mass percent of barium in the original sample
0.3163 g of barium ion were in a 4.534 g-sample. The mass percent of barium ion is:
0.3163 g/4.534 g × 100% = 6.976%
Step 6: Calculate the molar concentration barium in the 152 mL of solution
2.303 × 10⁻³ moles of barium ion were in 152 mL (0.152 L) of solution. The molarity of barium ion is:
M = 2.303 × 10⁻³ mol/0.152 L = 0.0152 M
Which characteristics describe the genetic code of humans? Select three options
Answer:
1. Can help in development of effective medications
2. Can help explain genetic diseases
3. Composed of about 19,000 genes
Explanation:
The other answer options are misleading.
Genetic code of humans can help with understanding more than just human genetics.
Human genetics is composed of 23 chromosome pairs, for a total of 46 chromosomes.
Using Beer's Law determine the concentration of a dye dissolved in water that has an absorptivity of 1 x 102 cm-1M-1 and produces an absorbance reading 1.0. The length of the cuvette is 1 cm.
Answer:
1 × 10⁻² M
Explanation:
Step 1: Given data
Absorptivity of a dye (ε): 1 × 10² cm⁻¹M⁻¹
Absorbance (A): 1.0
Length of the cuvette (l): 1 cm
Concentration of a dye (C): ?
Step 2: Calculate the concentration of the dye
We will use Beer's Law.
A = ε × l × C
C = A / ε × l
C = 1.0 / 1 × 10² cm⁻¹M⁻¹ × 1 cm
C = 1 × 10⁻² M
The concentration of the dye is 1 × 10⁻² M.
Why is digestion an example of both physical and chemical change simultaneously
Answer: Here is why,
Explanation: Burning of wood is a example of both physical and chemical change. ... Another example is digestion of food ,first the food is chewed into small pieces this is a chemical change while in the actual digestion process it is chemically broken with the help of digestive enzymes and saliva
Do all variations help organisms survive
Answer:
Yes
Explanation:
Or maybe i dont really know what it mean
3) A certain reaction has the following general form: A + B à AB At a particular temperature the concentration versus time were collected for this reaction, and a plot of ln[A]t versus time resulted in a straight line with a slope of −3.7 x 10−3 s−1. Show your math! (5 points) a. What is the order of the reaction? b. What is the rate constant (including units)? c. Calculate the half-life for the reaction. d. If the initial concentration of A is 0.250 M, what is the concentration after 220 seconds?
Answer:
a. First order.
b. [tex]k=3.7x10^{-3}s ^{-1}[/tex]
c. [tex]t_{1/2}=187.3s[/tex]
d. [tex][A]=0.111M[/tex]
Explanation:
Hello.
a. In this case since the slope is in s⁻¹ we can infer that the lineal form of the rate law is:
[tex]ln[A]=-kt+ln[A]_0[/tex]
Which is also:
[tex]y=mx+b[/tex]
It means that the reaction is first-order as slope equals the negative of the rate constant which also has units of first-oder reaction.
b. Since the slope is −3.7 x 10−3 s−1 the rate constant is:
[tex]k=-m\\\\k=-(-3.7x10^{-3}s ^{-1})\\\\k=3.7x10^{-3}s ^{-1}[/tex]
c. For first-order reactions, the half-life is:
[tex]t_{1/2}=\frac{ln(2)}{k}\\ \\t_{1/2}=\frac{ln(2)}{3.7x10^{-3}s^{-1}}\\\\t_{1/2}=187.3s[/tex]
d. In this case, since the integrated first-order rate law is:
[tex][A]=[A]_0exp(-kt)[/tex]
The concentration once 220 seconds have passed is:
[tex][A]=0.250Mexp(-3.7x10^{-3}s^{-1}*220s)\\\\[/tex]
[tex][A]=0.111M[/tex]
Regards.
An object accelerates 12.0 m/s2 when a force of 6.0 newtons is applied to it. What is the mass of the object?
Answer:
The mass of object is 0.5 Kg.
Explanation:
Given data:
Acceleration of object = 12.0 m/s²
Force on object = 6.0 N
Mass of object = ?
Solution:
Formula:
F = m×a
F = force
m = mass
a = acceleration
Now we will put the values in formula.
6.0 N = m × 12.0 m/s²
m = 6.0 N / 12.0 m/s²
( N = kg.m/s²)
m = 0.5 kg
The mass of object is 0.5 Kg.
How many grams of mgcl2 must be provided 1.89 mole of chloride ions
Answer:
Mass = 89.97 g
Explanation:
Given data:
Number of moles of chloride ions = 1.98 mol
Mass in grams of MgCl₂ present = ?
Solution:
we can see that 1 mole of MgCl₂ contain 2 moles of chloride ions. Thus 1.89 moles of chloride ions contain moles of MgCl₂ are,
Cl₂ : MgCl₂
2 : 1
1.89 : 1/2×1.89 = 0.945
Thus, 1.89 moles of chloride ions are provided by 0.945 moles of MgCl₂.
Mass of MgCl₂:
Mass = number of moles × molar mass
Mass = 0.945 mol × 95.211 g/mol
Mass = 89.97 g
When naming CoOH, which Roman numeral should be used?Immersive Reader
(A) I
(B) II
(C) III
(D) IV
PLZ HELP I'LL MARK BRAINLIEST
Answer:
coochie man? lol it's probably D or B :D
PLEASE HELPPP!!!!!!!!
Explanation:
Label A: oceanic - oceanic
Label B: oceanic - continental
Label C: continental - continental
Answer:
Oceanic-continental convergence---- letter B.
Oceanic-oceanic convergence ---- letter A.
Continental-continental convergence ---- letter C
plz mark brainliest
How can you use the periodic table to predict reactivity?
Giving Brainliest!!!
Answer:
hi
Explanation:
how r u today
Which type of investigation is based on observation?
Answer:
Quantitative Observations
Explanation:
A chemist dissolves 320.mg of pure nitric acid in enough water to make up 290.mL of solution. Calculate the pH of the solution. Be sure your answer has the correct number of significant digits.
Answer:
1.7
Explanation:
The formula to be used here is;
pH = -log[H⁺]
To determine the concentration of H⁺ of the nitric acid (HNO₃), formula for molarity is used
Molarity = number of moles/volume (in dm³ or L)
number of moles (n) = given mass/molar mass
Molar mass of HNO₃ = 1 + 14 + (16 x 3)
= 63g
given mass (in grams) = 320mg⇔0.32g (where 1000mg = 1g)
Thus; n = 0.32/63
n = 0.0051 moles
Volume of acid = 290 mL ⇔ 0.29 L (where 1000 mL = 1L)
Molarity = n/volume;
0.0051/0.29
Molarity = 0.018M
pH = -log 0.018
pH = 1.7
Rosa uses a microscope to look at a group of cells. She sees that the cells are joined together, so she knows that they are from one organism. She also sees that all of them have cell walls. Rosa could be looking at which type of cells?
Answer:
Mushroom cells
Explanation:
They are mushroom cells because they are together.
What is inside a Atom?
Answer:
there are three different subatomic particles inside them: the protons, neutrons, and electrons
The difference between the two types of succession !!!??!?
Answer:
Hope it help you
Stayhomestaysafe
Plz mark my answer brainliest✍️✍️
Explanation:
Primary succession is the series of community changes which occur on an entirely new habitat which has never been colonized before. For example, a newly quarried rock face or sand dunes. Secondary succession is the series of community changes which take place on a previously colonized, but disturbed or damaged habitat.
REAL NAME - SHRESTH DUBEY
What do you notice about the relationship between the force strength and the size of the velocity change?
Answer:
fkv SFHHHHHHHHHCB FSSSSZCHJjjjb .SFFHHHHHHHHC
Explanation:
What do you notice about the relationship between the force strength and the size of the velocity change?
Uuuuuuu
what is extraction .....???
Answer:
Extraction is the action of removing something.
Explanation:
(b) in the direct hydration method, ethene reacts with steam. The equation for this reaction is C2H4 + H2O = C2H5OH
State the temperature and pressure used in this reaction.
Answer:
20 degree and 4000000N
 what is 19.8-17.1
Answer: it should be 2.8
Explanation:
What will happen when the valve between a 2.00-L bulb, in which the gas pressure is 2.00 atm, and a 3.00-L bulb, in which the gas pressure is 4.50 atm, is opened? Assume the temperature remains constant. (For this question, label each statement as True or False and give an explanation/justification for each of your answers to receive credit. No credit is given for only True or False answers with no adequate justification. To receive credit you must provide justification. You may have to give numerical answers followed by verbal explanations. You can use any reasoning that you see fit but be as thorough as possible.)
The two gases will mix and react.
The two gases will remain separate and will not mix.
The two gases will occupy a volume of 5.0 L and the final pressure in the two bulbs will be 6.50 atm.
The two gases will occupy a volume of 5.0 L and the final pressure in the two bulbs will be 3.50 atm.
The two gases will occupy a volume of 5.0 L and the final pressure in the two bulbs will be 3.25 atm.
Answer:
- The two gases will mix and react.: FALSE.
- The two gases will remain separate and will not mix: FALSE.
- The two gases will occupy a volume of 5.0 L and the final pressure in the -two bulbs will be 6.50 atm.: FALSE.
- The two gases will occupy a volume of 5.0 L and the final pressure in the two bulbs will be 3.50 atm.: TRUE.
- The two gases will occupy a volume of 5.0 L and the final pressure in the two bulbs will be 3.25 atm: FALSE.
Explanation:
Hello.
In this case, given the options, since the total volume of the container includes the both of them, we find that:
- The two gases will mix and react: FALSE, since we do not know the identity of the gases which could be the same or two different inert gases.
- The two gases will remain separate and will not mix: FALSE, since as the valve is opened, the total gas will occupy the entire volume as the volume of a gas is the same to the container based on its constant molecules movements.
- The two gases will occupy a volume of 5.0 L and the final pressure in the two bulbs will be 6.50 atm: FALSE, since in this case, by using the Boyle's law for the first compartment we obtain the pressure of the gas there:
[tex]P_2V_2=P_1V_1\\\\P_2=\frac{P_1V_1}{V_2} =\frac{2.00atm*2.00L}{5.00L} =0.8atm[/tex]
Now, we reuse it for the gas at the 3.00-L bulb to find its final pressure:
[tex]P_2V_2=P_1V_1\\\\P_2=\frac{P_1V_1}{V_2} =\frac{2.00atm*3.00L}{5.00L} =2.7atm[/tex]
So the final pressure is:
[tex]P_{TOTAL}=0.8atm+2.7atm\\\\P_{TOTAL}=3.5atm[/tex]
- The two gases will occupy a volume of 5.0 L and the final pressure in the two bulbs will be 3.50 atm: TRUE considering the total pressure computed above.
- The two gases will occupy a volume of 5.0 L and the final pressure in the two bulbs will be 3.25 atm: FALSE since the final pressure is 3.5 atm.
Regards.
You have 100. grams of potassium bromide (KBr). How many moles do you have? (1 mole KBr = 119 g KBr)
0.840 mole KBr
1.00 mole KBr
1.19 mole KBr
2.00 mole KBr
Answer:
0.840
Explanation:
The 100 grams of KBr have been equivalent to 0.84 moles. Thus, option A is correct.
The moles can be defined as the mass of the compound with respect to the molecular mass. The moles can be given as:
Moles = [tex]\rm \dfrac{weight}{Molecular\;weight}[/tex]
The molecular weight has been the mass of the constituents of the atoms present in the compound.
The compound KBr has a molecular mass of 119 g/mol.
The given mass of the compound has been 100 grams.
The moles of KBr can be given as:
Moles of KBr = [tex]\rm \dfrac{100}{119}[/tex]
Moles of KBr = 0.84 moles.
The 100 grams of KBr have been equivalent to 0.84 moles. Thus, option A is correct.
For more information about the moles, refer to the link:
https://brainly.com/question/2437143
A beaker contains 42.0 mL of carbon tetrachloride ( CCl4 , density is 1.59 g/mL). Determine how many molecules of carbon tetrachloride are in the beaker.
Answer:
Number of molecules = 2.61 x 10²³
Explanation:
Given:
Volume of tetra-chloride = 42 ml
Density = 1.59 g/ml
Find:
Number of molecules
Computation:
Mass = Volume of tetra-chloride x Density
Mass = 42 x 1.59
Mass = 66.78
Molecular mass of tetra-chloride = 154 g/mol
Moles = 66.78 / 154
Moles = 0.4337
0.4337 mole = 0.4337 x Avogadro number
0.4337 mole = 0.4337 x 6.022 x 10²³
Number of molecules = 2.61 x 10²³
Which example describes a use for gemstones?
fabrics
plastics
drill bits
paper clips
I will give Brainlyest
Answer:
drill bits
Explanation:
I don't think that you would use gemstones in anything else.
True or false, the nucleus is the core of an atom
Answer:true
Explanation:
The neutrons and the protons are what stay there
Determine the milliliters of paint in a 5.0 gallon bucket
Ans: 18950 ML
Answer:
the answer is 18,927,06.
Explanation:
I just took the test ; )
How many days are in 5.75 weeks?
Answer:
There are 40.25 days in 5.75 weeks
Answer: 40.25
Hope this helped! :)
How many total atoms are in one molecule of maltose?
Answer:
The total number of atoms is 12 + 22 + 11 = 45, so carbon atoms are 12/45 of the total.
Explanation:
hydrogen peroxide slowly decomposes into water and oxygen.the enthalpy change of reaction can be calculated using standard enthalpies of formation.Using a Hess cycle what is the enthalpy change of reaction for this decomposition
In the warm up, you reviewed the equation to calculate
kinetic energy. What question could you ask about kinetic
energy which will include the variables that affect it?
Answer:
Can be used to do work,and it can be converted to potential.
Explanation:
Answer: can it be used to do work
Explanation: