Химия для вступительных экзаменов на сестринские программы: лист заданий с ответами

Which method separates two liquids with different boiling points, such as alcohol and water?

1. AUsing a magnet
2. BDistillation
3. CSieving
4. DFiltration

Что из перечисленного является физическим изменением?

1. AПоджаривание хлеба до коричневого цвета
2. BСкисание молока
3. CПревращение кипящей воды в пар
4. DРжавление железа

What is the change from a gas directly to a solid, skipping the liquid state, called?

1. ACondensation
2. BFreezing
3. CDeposition
4. DSublimation

A reaction is at equilibrium. More of one reactant is added. According to Le Chatelier's principle, what happens?

1. AThe reaction stops completely
2. BThe equilibrium shifts toward the products
3. CNothing changes
4. DThe equilibrium shifts toward the reactants

What is the formula of the hydroxide ion?

1. AOH⁺
2. BOH⁻
3. CH₃O⁺
4. DO²⁻

In the reaction Zn + Cu²⁺ → Zn²⁺ + Cu, which species loses electrons?

1. ACu
2. BCu²⁺
3. CZn
4. DZn²⁺

A scuba diver breathes compressed air deep underwater. Why must the diver breathe out while swimming up to the surface?

1. AThe air in the lungs expands as the outside pressure falls
2. BThe water gets warmer near the surface
3. COxygen turns to liquid at the surface
4. DThe air in the lungs shrinks as the outside pressure falls

Sugar is heated in a pan. Which observation shows that a chemical change, not just a physical change, has happened?

1. AIt turns black and gives off water vapour, leaving a solid that is no longer sweet
2. BThe crystals become smaller when crushed
3. CIt gets hot to the touch
4. DIt melts into a clear, runny liquid that sets again when it cools