Question

locs are present in a sample of HCl with a mass of 3.65g? 4. How many moles are present in a sa A. 3.46 moles B. 0.100 moles C. 2.19 X 1024 moles D. 10.0 moles 5. How many moles are present in 32.46g of AgNO3? A. 0.191 moles B. 5520 moles C. 5.23 moles D. 32.5 moles 6. How many molecules are present in 18.0g of MgSO4? A. 6.02 X 1023 B. 3.60 X 10-21 C. 4.03 X 1024 D. 9.00 X 1022 7. How many molecules are present in 0.340g of HCI? A. 1.78 X 10-22 B. 6.46 X 1025 C. 5.61 X 1021 D. 2.06 X 10-23 8. What is the percent by mass of carbon in carbon dioxide? A. 3.66% B. 366% C. 27.28% D. 42.9%

Answer 1

4)

Molar mass of HCl,
MM = 1*MM(H) + 1*MM(Cl)
= 1*1.008 + 1*35.45
= 36.458 g/mol


mass(HCl)= 3.65 g

use:
number of mol of HCl,
n = mass of HCl/molar mass of HCl
=(3.65 g)/(36.46 g/mol)
= 0.100 mol
Answer: B

5)

Molar mass of AgNO3,
MM = 1*MM(Ag) + 1*MM(N) + 3*MM(O)
= 1*107.9 + 1*14.01 + 3*16.0
= 169.91 g/mol


mass(AgNO3)= 32.46 g

use:
number of mol of AgNO3,
n = mass of AgNO3/molar mass of AgNO3
=(32.46 g)/(1.699*10^2 g/mol)
= 0.191 mol
Answer: A

Only 1 question at a time please. I have answered 1st two for you