Matter and Atomic Structure

How many protons (p), neutron (n) and electrons(e) are present in the Aurum isotope?

• 79 p 79 e 79 n

• 79 p 118 e 79 n

• 79 p 79 e 118 n

• 118 p 79 e 79 n

Determine the molar mass of Cu(NO₃)₂

• 186.7 grams per mol

• 186.7 grams

• 187.6 grams

• 187.6 grams per mol

One mole of H₂SO₄ has a mass of ?

• 98.1 grams

• 12 grams

• 90 grams

• 96.1 grams

The following statement is false about molar mass of an element except ?

• mass of one mole of an element compared to 12 grams of one atom of carbon-12.

• mass of one mole of an element compared to 1/12 mass of an atom carbon with mass of 12 grams.

• mass of one mole of a molecule compared to 12 grams of one atom of carbon-12.

• mass of one mole of a molecule compared to 1/12 mass of an atom carbon with mass of 12 grams.

Define empirical formula

• A chemical formula that shows the actual number of all atoms in a molecule.

• A chemical formula that shows the smallest ratio of all elements in a compound.

• A chemical formula that shows the highest ratio of all elements in a compound.

• A chemical formula that shows the actual number of all elements in a compound.

Calculate the relative molecular mass of MgSO₄.7H₂O ?

• 246.1 g/mol

• 120.1 g/mol

• 246.1

• 120.1

Determine x in the following hydrated compound formula, CuSO₄. xH₂O given that the relative molecular mass is 249.7.

• 5

• 6

• 7

• 8

_____________ is defined as number of solute dissolved per litre of solution.

• Molality

• Molarity

• Molal

• Mole fraction

If there is 12 litre of 0.25 M HCl solution, calculate the number of moles present.

• 0.3 moles

• 0.03 moles

• 3.00 moles

• 0.0003 moles

Determine the molality of a 0.04 moles of NaOH solution in 250 grams of water.

• 0.16 m

• 0.016 m

• 1.6 m

• 0.0016 m