Question: How many atoms are in .075 mol of titanium?

Answer: 4.5x10^22

Because There are 6.022x10^23 atoms per mole; therefore, (6.022x10^23*(0.075)=04.5x10^22 atoms of titanium.

Question: How many molecules are in 2.10 mol CO2?

Answer: 1.26x10^24

Because 2.10 mol x 6.02 * 10^23 molecules / mol

= 1.26 x 10^24 molecules CO2

Question: What is the number of moles in 9.63 L of H2S gas at STP?

Answer: 9.63L/22.4L.mole = 0.430 mole.

PV = nRT solve for n: n = PV/RT

n = 1 atm x 9.63L/0.08206Latm/molK x 273K = 0.430 mole

Question: What is the molar mass of (NH4)2CO3?

Answer: Just add up the molar masses of each atom:

N 2(14 g/mol) +

H 8(1 g/mol) +

C 1(12 g/mol) +

O 3(16 g/mol) =

96 g/mol

Question: What is the mass in grams of 5.90 mol C8H18?

Answer: mass = 5.90 x 114 =672.6g which can be rounded to 673g

Question: What is the number of moles in 432g Ba(NO3)2?

Answer: n = 432/261.3 = 1.65 mol

Question: What is the volume, in liters, of .500 mol of C3H8 gas at STP?

Answer: 1.783 g/L (22.4 L/1mole) = 39.94 g/mole

Question: What is the mass in grams of 6.9 mol of C8H18?

Answer: (6.90 mol C8H18) x (114.22929 g C8H18/mol) = 788 g C8H18

Question: How do you calculate the number of moles in 8.15x10^15 atoms of 14-N ?

Answer: (8.15 x 10^15 atoms)/(6.022 x 10^23 atoms)

= 1.35 x 10^-8 moles 14-N

(56.35 kg)(1000 g/kg) = (56350 g)(1 mol/47.867 g)

= 1177. moles Ti

(4.80 x 10^-6 g)(1 mol/74.92160 g) = 6.41 moles As

Question: What is the molar mass of (NH3)?

Answer: There is one Nitrogen= one atom of nitrogen is 14.00

There are three Hydrogen= one atom of hydrogen= 1

14.00x1- 14.00

1x3= 3 add both together (14.00+3)

atomic weight or molar mass= 17