Chemistry for nursing entrance exams worksheet with answers

What kind of carbon–carbon bonds do alkanes contain?

1. AAt least one triple bond
2. BIonic bonds
3. CAt least one double bond
4. DOnly single bonds

How is percent yield calculated?

1. A(Theoretical yield ÷ actual yield) × 100
2. B(Actual yield ÷ theoretical yield) × 100
3. C(Mass of reactants ÷ mass of products) × 100
4. DActual yield − theoretical yield

Which of these is a physical change?

1. AMilk turning sour
2. BWater boiling into steam
3. CBread being toasted until brown
4. DIron rusting

What is the formula of sodium sulfate, made from Na⁺ and SO₄²⁻ ions?

1. ANaSO₄
2. BNa(SO₄)₂
3. CNa₂SO₄
4. DNa₄SO₂

What does a buffer solution do?

1. AIt turns any acid into a strong base
2. BIt speeds up neutralisation reactions so that the pH quickly reaches exactly 7
3. CIt resists pH changes when a little acid or base is added
4. DIt keeps the temperature of a solution constant

Sulfur has 16 electrons. In which period of the periodic table is it?

1. APeriod 3
2. BPeriod 6
3. CPeriod 2
4. DPeriod 16

Which of these is a weak acid?

1. ANitric acid
2. BAcetic acid (in vinegar)
3. CHydrochloric acid
4. DSulfuric acid

Gently heating DNA separates its two strands, but each strand stays in one piece. Why?

1. AThe two strands are joined by ionic bonds that melt first
2. BEach strand is held together by hydrogen bonds, while the two strands are joined by covalent bonds
3. CHeat converts DNA into a protein
4. DThe strands are held together by weak hydrogen bonds, while each strand's backbone is covalent