Q2.
This question is about metals and metal compounds.
(a)
Copper oxide reacts with hydrochloric acid to produce copper chloride and water.
Copper oxide is insoluble in water.
Copper oxide is gradually added to hydrochloric acid until in excess.
Magnesium reacts with hydrochloric acid to produce magnesium chloride and hydrogen.
Plan an investigation to find the accurate volume of hydrogen produced from
magnesium
You do not need to write about safety precautions.
Answer:
sry I don't know the answer
Calculate the average atomic mass for element X.
(Please HELP)
Select the correct answer.
0.22 M
HCI
Unknown
LiOH
What is the concentration of the base (LIOH) in this titration?
1.0 ml
0.5 ml
Initial
burette
reading
Final
burette
reading
13.3 ml
18.5 ml
OA
0.16 M
ОВ.
0.15 M
OC. 0.22 M
OD
18 M
O E
0.5 M
Daset
Answer:
=0.15M
Explanation:
To get the moles of the unknown LiOH, calculate the number of moles of HCl in 12.3mL.
Using the stoichiometric coefficient, mole ratio 1:1.
This means that the number of moles is the same. This number of moles is contained in 18mL. Then Calculate the molarity (concentration) which is in 1000mL
See the explanation from the image I have shared with you for calculations.
The normal boiling point of ethanol is 78.4 oC. Its enthalpy of vaporization is 38.6 kJ/mol. Estimate the vapor pressure of ethanol at 26.3 oC.
Answer: The vapor pressure of ethanol at [tex]26.3^{o}C[/tex] is 238.3 torr.
Explanation:
Given: [tex]\Delta H_{vap}[/tex] = 38.6 kJ/mol
[tex]T_{1} = 26.3^{o}C = (26.3 + 273) K = 299.3 K[/tex]
[tex]T_{2} = 78.4^{o}C = (78.4 + 273) K = 351.4 K[/tex]
Formula used to calculate the vapor pressure of ethanol is as follows.
[tex]ln\frac{P_{2}}{P_{1}} = \frac{\Delta H_{vap}}{R} [\frac{1}{T_{1}} - \frac{1}{T_{2}}]\\[/tex]
Substitute the values into above formula as follows.
[tex]ln\frac{P_{2}}{P_{1}} = \frac{\Delta H_{vap}}{R} [\frac{1}{T_{1}} - \frac{1}{T_{2}}]\\ \\ln \frac{760 torr}{P_{1}} = \frac{38600 J}{8.314 J/mol K}[\frac{1}{299.3} - \frac{1}{351.4}]\\\frac{760}{P_{1}} = 3.18\\P_{1} = 238.3 torr[/tex]
Thus, we can conclude that the vapor pressure of ethanol at [tex]26.3^{o}C[/tex] is 238.3 torr.
Which has more mass, 2 kg of steel or 5 kg of feather.
Answer:
5 kg of feather
Explanation:
HELP HELP HELP PLSSS
Answer:
the answer is c kept in blue and with light
Look at this balanced chemical reaction: N2 + 3H2 2NH3
How many grams of ammonia can be produced from reacting a 450 L sample of nitrogen gas at a temperature of 450 K and a pressure of 300 atm?
Answer: A mass of 124457.96 g ammonia is produced by reacting a 450 L sample of nitrogen gas at a temperature of 450 K and a pressure of 300 atm.
Explanation:
Given: Volume = 450 L
Temperature = 450 K
Pressure = 300 atm
Using ideal gas equation, moles of nitrogen are calculated as follows.
PV = nRT
where,
P = pressure
V = volume
n = no. of moles
R = gas constant = 0.0821 L atm/mol K
T = tempertaure
Substitute values into the above formula as follows.
[tex]PV = nRT\\300 atm \times 450 L = n \times 0.0821 L atm/mol K \times 450 K\\n = \frac{135000}{36.945}\\= 3654.08 mol[/tex]
According to the given equation, 1 mole of nitrogen forms 2 moles of ammonia. So, moles of ammonia formed by 3654.08 moles of nitrogen is as follows.
[tex]2 \times 3654.08 mol\\= 7308.16 mol[/tex]
As moles is the mass of substance divided by its molar mass. So, mass of ammonia (molar mass = 17.03 g/mol) is as follows.
[tex]Moles = \frac{mass}{molar mass}\\7308.16 = \frac{mass}{17.03 g/mol}\\mass = 124457.96 g[/tex]
Thus, we can conclude that a mass of 124457.96 g ammonia is produced by reacting a 450 L sample of nitrogen gas at a temperature of 450 K and a pressure of 300 atm.
What is the valency of Aluminium and nitrate in Al(NO3)3 ?
Answer:xl/ck xLKsx
Explanation:sl/cs c/ls
What characteristic of an atom influences the behavior of the valence electron the most in an atom?
(Hint: Consider the charge of the particles)?
Answer:
The higher its electronegativity, the more an element attracts electrons.
Explanation:
Electronegativity is a property that describes the tendency of an atom to attract electrons (or electron density) toward itself. An atom's electronegativity is affected by both its atomic number and the size of the atom.
A train is accelerating at a rate of 2 m/s. If its intital velocity is 20 m/s,what is its veolcity after 30 seconds
Answer:
80 m/s.
Explanation:
NOTE: This is a physics question. However, the solution to the question given below:
From the question given above, the following data were obtained:
Acceleration (a) = 2 m/s²
Initial velocity (u) = 20 m/s
Time (t) = 30 s
Final velocity (v) =?
The final velocity of the train can be obtained as shown below:
v = u + at
v = 20 + (2 × 30)
v = 20 + 60
v = 80 m/s
Therefore, the final velocity of train is 80 m/s.
What is the percent by volume of alcohol, in a solution containing 24 mL of alcohol dissolved in 90 mL of water?
Answer:
use this formula it will help u .
Explanation:
If 60 ml of ethanol is diluted to a final volume of 400 ml, you create a 35 % ethanol solution.
First, realize that you creating a solution with that contains a polar solute (ethanol) with a polar solvent (water). Remember that "like dissolves like."
If you pour 60 ml of ethanol in a volumetric flask, you add 340 ml of water to dilute this solution to a final volume of 400 ml.
Volumetric flasks are designed to make or dilute solutions to specified final volume.
Since you have 60 ml of ethanol in a total solution of 400 ml, the percentage of ethanol is 35 %.
This result is obtained in the following manner.
ml/400. ml. = .35
.35 x 100% = 35 %
What does binding energy measure?
A. The forces attracting electrons to a nucleus
B. The repelling forces pushing protons apart
C. The energy used to hold the nucleus together
D. The energy released in radioactive decay
Answer:
C. the energy used to hold the nucleus together
An iron block of mass 18 kg is heated from 285 K to 318 K. If 267.3 kJ is required, what is the specific heat of iron?
A. 490.05
B. 158.77
C. 145.80
D. 450.00
Answer:
D. 450 J/kgK
Explanation:
Using the formula as follows:
Q = m × c × ∆T
Where:
Q = amount of heat absorbed/released (J)
m = mass of substance (g)
c = specific heat capacity
∆T = change in temperature (°C)
According to the information provided in this question:
Q = 267.3 kJ = 267300J
m = 18kg
∆T = 318K - 285K = 33K
c = ?
Q = m × c × ∆T
c = Q ÷ m∆T
c = 267300 ÷ 18 × 33
c = 267300 ÷ 594
c = 450 J/kgK
An atom has9 electrons and 9 protons at the start. If it loses 2 electrons, what would the net charge on the atom be
Answer:
i hope it will help you
Explanation:
there will be 7 electrons and 9 protons will have 2+ charge.
he ______ is the depth in the ocean at which calcareous skeletal material first begins to dissolve. Multiple choice question.
Answer: lysocline
Explanation:
Lysocline is the depth in the ocean at which calcareous skeletal material first begins to dissolve. It is the depth of the ocean whereby the dissolution rate of calcite has a dramatic rise.
Lysocline is also referred to as the transition zone upper bound where the CaCO3 content drops.
name a food that contain an acid
Answer:
name a food that contain an acid
1. nuts
2. dairy
3. grains
3. meat
these are the foods which contains acids.
hope its helps you
have a great day keep smiling be happy stay safe.
Identify each as measurement for area, volume, density, time, mass temp, length: ns, 12g/ml,
1.8pm, 250m2 ,325K and 5.4mL and 90kg
Answer:
ns - time
12g/ml - density
1.8pm - length
250m2 - area
325K - temperature
5.4mL - volume
90kg - mass
Explanation:
The unit of measurement is used to identify what a measurement is. It is very important to place a specific unit for each measurement made as it distinguishes them from one another. In this question, various measurements were given, which can be identified using their units.
- ns is measurement for time because seconds (s) is its unit
- 12g/ml is measurement for density because grams/milliliters (g/mL) is its unit
- 1.8pm is measurement for length because length can be measured in picometer (pm).
- 250m2 is measurement for area because metre² (m²) is its unit.
- 325K is measurement for temperature because Kelvin is the absolute unit for temperature.
- 5.4mL is measurement for volume because volume can be measured in milliliters (ml).
- 90kg is measurement for Mass because kilograms (s) is its unit.
Question 3 of 10 What does the first ionization energy represent? O A. The energy required to add an electron to a new energy level B. The energy to remove an energy level of electrons O C. The energy given off when an electron is gained D. The energy required to remove an electron from an atom SUBMIT
Answer:
D
Explanation:
The first ionization energy is the minimum energy required to remove the most loosely bound electron from an atom.
Good luck!
Balance the equation for
__Ca+__Pb(NO3)2—__Pb+__Ca(NO3)2
Answer:
Ca + Pb(NO3)2 → Pb + Ca(NO3)2
Explanation:
This is an oxidation-reduction (redox) reaction:
PbII + 2 e- → Pb0
(reduction)
Ca0 - 2 e- → CaII
(oxidation)
Pb(NO3)2 is an oxidizing agent, Ca is a reducing agent.
A gamma wave has____
energy than a radio wave.
A television wave has a
th
Answer:
more
Explanation:
seems like you did not finish the questions
What dose science do
Explanation:
Science, any system of knowledge that is concerned with the physical world and its phenomena and that entails unbiased observations and systematic experimentation. In general, a science involves a pursuit of knowledge covering general truths or the operations of fundamental laws.
You burn a log on a fire. You use fire to warm yourself and help you see to read a book. What energy transformation is taking place?
Answer:
heat energy to keep you warm and light energy to be able to read your book
Explanation:
The work function of an element is the energy required to remove an electron from the surface of the solid. The work function for palladium is 503.7 kJ/mol (that is, it takes 503.7 kJ of energy to remove 1 mole of electrons from 1 mole of Pd atoms on the surface of Pd metal). What is the maximum wavelength of light that can remove an electron from an atom in palladium metal
Answer:
λ = 2.38 × 10^(-7) m
Explanation:
We are given the work function for palladium as 503.7 kJ/mol.
Now let's convert this to KJ/electron.
We know from avogadro's number that;
1 mole of electron = 6.022 × 10^(23) electrons
Thus,
503.7 kJ/mol = 503.7 × 1/(6.022 × 10^(23)) = 8.364 × 10^(-22) KJ/electron = 8.364 × 10^(-19) J/electron
Formula for energy of a photon is;
E = hv
Where;
h is Planck's constant = 6.626 × 10^(-34) J.s
v is velocity
Now, v = c/λ
Where;
c is speed of light = 3 × 10^(8) m/s
λ is wavelength of light.
Thus;
E = hc/λ
Making λ the subject, we have;
λ = hc/E
λ = (6.626 × 10^(-34) × 3 × 10^(8))/(8.364 × 10^(-19))
λ = 2.38 × 10^(-7) m
A new element R shows chemical properties similar to the element sodium. What is the correct formula of a compound formed with R and sulfur?
R₂S
RS₂
RS
R₂S₂
Answer:
R2S this is because sodium has one 1 valence and sulfur has valence of 2 so when they combine theyinterchange their valence
Lead is a toxic metal that affects the central nervous system. A Pb-contaminated water sample contains 0.0012 % Pb by mass. What volume of the water in milliliters contains 100 mg of Pb
Answer:
8.3 × 10³ mL
Explanation:
Step 1: Calculate the mass of water that contains 100 mg of Pb
The concentration of Pb in the sample is 0.0012% by mass, that is, there are 0.0012 g of Pb every 100 g of water. The mass of water that contains 100 mg (0.100 g) of Pb is:
0.100 g Pb × 100 g Water/0.0012 g Pb = 8.3 × 10³ g Water
Step 2: Calculate the volume corresponding to 8.3 × 10³ g of water
Since the solution is diluted, we will assume the density of the sample is equal than the density of water (1 g/mL).
8.3 × 10³ g × 1 mL/1 g = 8.3 × 10³ mL
The volume of the water in milliliters contains 100 mg of Pb is;
V = 8.3 × 10³ mL
Volume of SolutionWe are given the concentration of Pb in the sample as 0.0012% by mass.
That means that there are 0.0012 g of Pb in every 100 g of water.
Thus, the mass of water that contains 100 mg (0.100 g) of Pb is calculated as;
(0.100 g Pb × 100 g of Water)/0.0012 g of Pb = 8.3 × 10³ g of Water
Now, we know that the density of water (1 g/mL) but we are not given the density of the sample.
Thus, since the solution is diluted we can equally say that;
Density of sample = 1 g/mL
Formula for Volume is;
V = mass/density
Thus;
V = 8.3 × 10³ g/1 g/mL
V = 8.3 × 10³ mL
Read more about Volume of solution at; https://brainly.com/question/17055828
The enthalpy of a reaction is -394 kJ/mol. How would you describe the
reaction?
A. Spontaneous
B. Exothermic
C. Endothermic
D. Nonspontaneous
Answer:
the reaction is spontaneous
Help me and I'll make u Brainliest eat and follow u
19. place moth balls in the closet and observe after several days.
20. whenever wax or a candle burns it turns from solid to liquid but again at room temperature it turns to solid
21. evaporation, condensation, precipitation
22. it produces new substances
23. vinegar Bubbles when baking soda is added
24. steam
Describe 5 importance matter to undergo changes
Answer:
melting, freezing, sublimation, deposition, condensation, and vaporization. These changes
Explanation:
hope it helps...i dont know if its right but i hope it helps
A 20.0 mL solution of NaOH is neutralized with 24.1 mL of 0.200 M HBr. What is the concentration of the original NaOH solution
Answer:
0.241 M
Explanation:
We'll begin by writing the balanced equation for the reaction. This is given below:
HBr + NaOH —> NaBr + H₂O
From the balanced equation above,
The mole ratio of acid, HBr (nₐ) = 1
The mole ratio of base, NaOH (n₆) = 1
Finally, we shall determine the concentration of the NaOH solution. This can be obtained as follow:
Volume of base, NaOH (V₆) = 20 mL
Volume of acid, HBr (Vₐ) = 24.1 mL
Concentration of acid, HBr (Cₐ) = 0.2 M
Concentration of base, NaOH (C₆) =?
CₐVₐ / C₆V₆ = nₐ/n₆
0.2 × 24.1 / C₆ × 20 = 1/1
4.82 / C₆ × 20 = 1
Cross multiply
C₆ × 20 = 4.82
Divide both side by 20
C₆ = 4.82 / 20
C₆ = 0.241 M
Therefore, the concentration of the NaOH solution is 0.241 M
Write a hypothesis to answer the lesson question
"How can electrolysis be used to separate a
compound into its components?"
If_____ (an electrical current, a salt, an electrode, or oxygen)?
is applied to water
containing an electrolyte, then the water will
decompose into____( water vapor, sodium gas, hydrogen gas, oxygen gas, hydrogen and oxygen gas)?
because____________?
Answer:
Electric current
Hydrogen and oxygen gas
Explanation:
Electrolysis is defined as a method of separation whereby an electric current is introduced into compounds to separate them . The electric current used here is a direct electric current (DC) and it makes the compound to be spit into its' component elements.
Now, in the case of water like it says in the question. Water is a mixture of hydrogen and oxygen gas. Thus, when electric current is passed through water which has an Electrolyte, it makes the water to decompose into its compound elements which are hydrogen and oxygen.