Робочий аркуш «Хімія для вступних іспитів на медсестринство» з відповідями

Which of these is a polyatomic ion?

1. ASodium, Na⁺
2. BChloride, Cl⁻
3. COxide, O²⁻
4. DSulfate, SO₄²⁻

What is a hydrocarbon?

1. AA compound made of hydrogen and oxygen
2. BAny compound that dissolves in water
3. CA carbon atom with a positive charge
4. DA compound made of only hydrogen and carbon

What is an empirical formula?

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

A red blood cell is placed in a concentrated (hypertonic) salt solution. What happens?

1. AThe cell stays the same size and shape
2. BWater enters the cell, which swells and may burst
3. CSalt leaves the cell, which swells
4. DWater leaves the cell, which shrinks

Which coefficients balance __KClO₃ → __KCl + __O₂?

1. A2, 1, 3
2. B1, 1, 3
3. C2, 2, 3
4. D1, 1, 1

In a reaction at equilibrium, a product is continuously removed. What happens?

1. AThe reaction rate drops to zero
2. BMore product keeps forming as the equilibrium shifts to the right
3. CThe equilibrium shifts to the left to form more reactants
4. DThe reactants run out immediately

At the top of a high mountain, air still contains about 21% oxygen. Why do climbers still get less oxygen with each breath?

1. AThe percentage of oxygen in the air falls sharply as you climb higher
2. BCold air contains no oxygen
3. COxygen is heavier, so it all sinks to sea level
4. DThe total air pressure is lower, so the partial pressure of oxygen is lower

How many millilitres of 0,2 M NaOH are needed to neutralise 25 mL of 0,1 M HCl?

1. A5 mL
2. B25 mL
3. C50 mL
4. D12,5 mL