1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Tcecarenko [31]
3 years ago
7

Each student in a class placed a 2.00 g sample of a mixture of Cu and Al in a beaker and placed the beaker in a fume hood. The s

tudents slowly poured 15.0 mL of 15.8 M HNO3 into their beakers. The reaction between the copper in the mixture and the HNO3 is represented by the equation above. The students observed that a brown gas was released from the beakers and that the solutions turned blue, indicating the formation of Cu 2. The solutions were then diluted with distilled water to known volumes. The students determined that the reaction produced 0.010 mol of Cu(NO3)2. Based on the measurement, what was the percent of Cu by mass in the original 2.00 g sample of the mixture
Chemistry
1 answer:
Aleks [24]3 years ago
3 0

Answer:

Percentage mass of copper in the sample = 32%

Explanation:

Equation of the reaction producing Cu(NO₃) is given below:

Cu(s)+ 4HNO₃(aq) ---> Cu(NO₃)(aq) + 2NO₂(g) + 2H₂O(l)

From the equation of reaction, 1 mole of Cu(NO₃) is produced from 1 mole of copper. Therefore, 0.010 moles of Cu(NO₃) will be produced from 0.010 mole of copper.

Molar mass of copper = 64 g/mol

mass of copper = number of moles * molar mass

mass of copper = 0.01 mol * 64 g/mol = 0.64 g

Percentage by mass of copper in the 2.00 g sample = (0.64/2.00) * 100%

Percentage mass of copper in the sample = 32%

You might be interested in
What pressure, in atm, would be exerted by 0.023 grams of oxygen (O2) if it occupies 31.6 mL at 91
Vikentia [17]

Answer:  A pressure of 0.681 atm would be exerted by 0.023 grams of oxygen (O_2) if it occupies 31.6 mL at 91^{o}C.

Explanation:

Given : Mass of oxygen = 0.023 g

Volume = 31.6 mL

Convert mL into L as follows.

1 mL = 0.001 L\\31.6 mL = 31.6 mL \times \frac{0.001 L}{1 mL}\\= 0.0316 L

Temperature = 91^{o}C = (91 + 273) K = 364 K

As molar mass of O_2 is 32 g/mol. Hence, the number of moles of O_2 are calculated as follows.

No. of moles = \frac{mass}{molar mass}\\= \frac{0.023 g}{32 g/mol}\\= 0.00072 mol

Using the ideal gas equation calculate the pressure exerted by given gas as follows.

PV = nRT

where,

P = pressure

V = volume

n = number of moles

R = gas constant = 0.0821 L atm/mol K

T = temperature

Substitute the value into above formula as follows.

PV = nRT\\P  \times 0.0316 L = 0.00072 mol \times 0.0821 L atm/mol K \times 364 K\\P = \frac{0.00072 mol \times 0.0821 L atm/mol K \times 364 K}{0.0316 L}\\= 0.681 atm

Thus, we can conclude that a pressure of 0.681 atm would be exerted by 0.023 grams of oxygen (O_2) if it occupies 31.6 mL at 91^{o}C.

4 0
3 years ago
A 33.69 g sample of a substance is initially at 29.4 °c. after absorbing 1623 j of heat, the temperature of the substance is 110
Sliva [168]
Q= mcΔT
1623 = 33.69g x c x (110.8 - 29.4)
1623 = 2742.366 g•°C x c
c = 0.59j/g•°C
4 0
3 years ago
Provide the name(s) for the tertiary alcohol(s) with the chemical formula C6H14O that have a 4-carbon chain. Although stereochem
pochemuha

Answer:

Explanation:

A tertiary alcohol is a compound (an alcohol) in which the carbon atom that has the hydroxyl group (-OH) is also bonded (saturated) to three different carbon atoms.

Based on the question, the only <u>tertiary alcohol that can result from C₆H₁₄O that have a 4-carbon chain</u> is

2-hydroxy-2,3-dimethylbutane

     H  OH   H    H

      |     |       |      |

H - C - C -   C  - C - H

      |     |       |      |

     H  CH₃  CH₃ H

From the above, we can see that the carbon atom having the hydroxyl group is also bonded to three other carbon atoms. And since we aren't considering stereochemistry, this is the only tertiary alcohol we can have with a 4-carbon chain

4 0
3 years ago
can any body tell me what is the relation in between halogen group and van der wals foce of attraction.why it increase down the
Volgvan
Because the size of atoms increase as you move down the periodic table.
5 0
3 years ago
Read 2 more answers
How many grams of Iron (III) oxide (Fe2O3) can be produced from 25.0 g of iron and an excess of oxygen?
Masja [62]

Answer:

2.3

Explanation:

cause im right boyyyyyyyu

8 0
2 years ago
Other questions:
  • Moises performs a chemical reaction according to the reaction
    10·1 answer
  • PLEASE HELP ME QUICK
    5·1 answer
  • To find density of an object what 2 things are needed?
    8·1 answer
  • Which law relates to the ideal gas law? P 1 T 1 =P 2 T 2 P 1 n 1 =P 2 n 2 V 1 Omega 1 = V 2 n 2 P 1 V 1 = P 2 V 2
    13·1 answer
  • Does gravity exist without air?
    5·1 answer
  • 8 bananas weigh 1pound and sale price is 4 pounds for $5. How much it cost me to buy 25 bananas?
    6·1 answer
  • AL(OH)3+ HCI—&gt; ALCL3 +H2O
    12·1 answer
  • 1. What would be the molarity of the sodium ion in solution.​
    15·1 answer
  • 200.0 mL of a 0.845 M solution of KCl is diluted to 600.0 mL. What is the new concentration of the solution?
    15·1 answer
  • Ammonia and hydrogen fluoride both have unusually high boiling points due to
    5·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!