Quantitative Chemistry

What is the relative molecular mass (Mr) of water (H₂O)? (Atomic masses: H=1, O=16)

Which of the following represents the correct formula to calculate the number of moles?

If 12 g of carbon reacts completely with oxygen to form CO₂, what mass of CO₂ is formed? (Atomic masses: C=12, O=16)

What is the percentage composition of oxygen in calcium carbonate (CaCO₃)? (Atomic masses: Ca=40, C=12, O=16)

Which of the following is the correct mole ratio in the reaction: 2H₂ + O₂ → 2H₂O?

How many moles are present in 22 g of CO₂? (Atomic masses: C=12, O=16)

In the reaction 4Al + 3O₂ → 2Al₂O₃, how many moles of oxygen are needed to react completely with 8 moles of aluminium?

What volume of hydrogen gas (at STP) is produced when 2 g of zinc reacts with dilute hydrochloric acid? (Atomic masses: Zn=65, 1 mole of gas occupies 22.4 L at STP)

Calculate the empirical formula of a compound containing 40% sulfur and 60% oxygen by mass. (Atomic masses: S=32, O=16)

What is the mass of 0.5 moles of sodium chloride (NaCl)? (Atomic masses: Na=23, Cl=35.5)