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

В какой группе находятся благородные газы, например гелий и неон?

1. AВ группе 1
2. BВ группе 18
3. CВ группе 17
4. DВ группе 2

Почему воду часто называют универсальным растворителем?

1. AЭто единственная жидкость на Земле
2. BВ её молекуле нигде нет частичных зарядов, поэтому она смешивается со всем
3. CОна полностью растворяет любое вещество
4. DОна растворяет больше веществ, чем другие распространённые жидкости

What is an empirical formula?

1. AA drawing of how the atoms are bonded
2. BThe simplest whole-number ratio of atoms in a compound
3. CThe mass of one mole of a compound
4. DThe actual number of each atom in one molecule

How does evaporation differ from boiling?

1. AEvaporation produces a solid, while boiling produces a gas
2. BEvaporation needs a higher temperature than boiling
3. CEvaporation happens throughout the liquid at a set temperature; boiling happens only at the surface
4. DEvaporation happens only at the surface and at any temperature; boiling happens throughout the liquid at a set temperature

An exothermic reaction is at equilibrium. What happens if the temperature is raised?

1. AThe equilibrium does not change
2. BThe equilibrium shifts toward the reactants
3. CThe equilibrium shifts toward the products, raising the yield
4. DThe reaction becomes endothermic

A solution has a pH of 2. What is its hydrogen ion concentration?

1. A1 × 10⁻¹² mol/L
2. B1 × 10⁻² mol/L
3. C1 × 10² mol/L
4. D2 mol/L

A gas occupies 4 L at 2 atm and 200 K. What is its volume at 1 atm and 400 K?

1. A8 L
2. B4 L
3. C16 L
4. D1 L

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

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