Number of Moles and Mass Practice Questions

Number of Moles and Mass Practice Questions
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Question 1

Calculate the number of moles contained in 120 g of phosphoric acid (H3PO4). The molar mass of phosphoric acid is 98 g.mol-1.

Question 2

Calculate the mass of 0.025 moles of H2SO4. The atomic masses of hydrogen (H), sulphur (S), and oxygen (O) are 1 amu, 32 amu, and 16 amu respectively.

Question 3

Calculate the mass of 0.25 moles of potassium dichromate (K2Cr2O7). The atomic masses of potassium (K), chromium (Cr), and oxygen (O) are 39 amu, 52 amu, and 16 amu respectively.

Question 4

Which of the following contains more moles? 12 g of SO2 or 12 g of CH4 (Atomic mass: Sulphur (S) = 32 amu, Oxygen (O) = 16 amu, Hydrogen (H) = 1 amu)

Question 5

1- Calculate the volume occupied by 1.5 moles of nitrogen gas at 27°C and a pressure of 2 bar. The value of R is 0.083 bar dm3.mol-1.K-1.

2- If the temperature increases by 35% but the pressure decreases by 20%, what would the new volume of gas be?