Moles to Mass and Mass to Moles

A student calculated the number of moles of methane (CH4) present in a 100g sample of a gaseous mixture. If the student determined that there’s 0.6 moles of methane present in the sample, what is the percent composition of methane in the sample?

• .096%

• 9.6%

• .9%

• 90%

Calculate the number of atoms in 0.0340 g Zn.

• 5.200 x 10^-4 atoms Zn

• 3.130 x 10²³ atoms Zn

• 3.130 x 10²⁰ atoms Zn

• 1 atom Zn

Tags

NGSS.HS-PS1-7

Which of the following methods should be used in order to calculate the molar mass of magnesium hydroxide?

• Add the masses of two moles Mg to the mass of one mole OH

• Add the total protons and neutrons.

• Add the masses of one mole Mg to the mass of one mole OH

• Add the masses of one mole Mg to the masses of two moles of OH.

Tags

NGSS.HS-PS1-7

How many moles of carbon atoms are there in 5g of carbon?

• 60 mol

• 17 mol

• 0.42 mol

• 7 mol

How many moles are there in 12.7g of CaF₂?

• 0.20 mol

• 1,000.76 mol

• 6.14 mol

• 0.16 mol

How many grams of carbon dioxide are in 0.5 mol of carbon dioxide?

• 11 g

• 44.009 g

• 22.005 g

• 88.018 g

Calculate the mass of 0.25 mol of carbon dioxide molecules. (M_r: CO₂ = 44) (Higher Tier Question)

• 33 g

• 11 g

• 12 g

• 16 g

Calculate the number of moles of water molecules in 36 g of water. (M_r: H₂O = 18) (Higher Tier Question)

• 2 mol

• 0.5 mol

• 18 mol

• 16 mol

What is the mass of 1 mole of water?

(Higher Tier Question)

• 16 g

• 2 g

• 18 g

• 6.02 g

Using the balanced chemical equation: Mg + 2 HCl --> MgCl₂ + H₂ How many grams of MgCl₂ is produced if 4.67 moles of HCl react?

• 219 g MgCl₂

• 4.67 g MgCl₂

• 94 g MgCl₂

Tags

NGSS.HS-PS1-7