CBA 4 Chemistry Review

Front

What does it mean if there is no subscript following an element symbol in a chemical formula?

Back

It means there is only 1 atom of that element present.

Front

How do you determine the number of atoms of an element in a compound with a coefficient?

Back

Multiply the coefficient by the subscript of the element. If there is no subscript, it is 1.

Front

In the compound 6NaCl, how many Sodium (Na) atoms are present?

Back

There are 6 Sodium (Na) atoms.

Front

In the compound 10MgCl₂, how many Magnesium (Mg) atoms are present?

Back

There are 10 Magnesium (Mg) atoms.

Front

How many Hydrogen atoms are in the compound 3(NH₄)₂CrO₄?

Back

There are 24 Hydrogen atoms.

Front

What is the law of conservation of mass in a chemical reaction?

Back

The law states that mass is neither created nor destroyed in a chemical reaction; the total mass of reactants equals the total mass of products.

Front

If a reaction starts with 20g of reactants, what should be the total mass of the products?

Back

The total mass of the products should also be 20g.

Front

What is a coefficient in a chemical equation?

Back

A coefficient is a number placed in front of a chemical formula to indicate how many molecules or moles of that substance are present.

Front

What is a subscript in a chemical formula?

Back

A subscript is a number written below and to the right of an element symbol that indicates the number of atoms of that element in a molecule.

Front

How do you calculate the total number of atoms in a compound?

Back

Add the number of atoms of each element, taking into account the coefficients and subscripts.