Amounts of substances in equations

Question 1

How can you calculate the masses of reactants and products in chemical reactions?

Answer 1

From balanced symbol equations.

Question 2

How can chemical equations be interpreted in terms of moles?

Answer 2

For example, the equation Mg + 2HCI - MgCI2 + H2 shows that one mole of magnesium reacts with two moles of hydrochloric acid to produce one mole of magnesium chloride and one mole of hydrogen gas.

Question 3

What skills should students develop regarding chemical equations?

Answer 3

They should be able to calculate the masses of substances shown in a balanced symbol equation and calculate the masses of reactants and products using the balanced symbol equation and the mass of a given reactant or product.

Question 4

What mathematical skills are necessary for these calculations?

Answer 4

Recognizing and using expressions in decimal form, using ratios, fractions, and percentages, changing the subject of an equation, and substituting numerical values into algebraic equations with appropriate units for physical quantites