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

What does the octet rule state?

1. AAtoms tend to gain, lose or share electrons to get 8 outer electrons
2. BEvery stable molecule contains exactly 8 atoms
3. CEvery stable atom has exactly 8 protons in its nucleus
4. DAn atom can form a maximum of 8 covalent bonds

What causes the pressure of a gas in a container?

1. AGas particles sticking to the walls
2. BThe weight of the container pressing on the gas inside
3. CGas particles stopping and pushing outward
4. DGas particles colliding with the container walls

What is a single covalent bond?

1. ATwo pairs of electrons shared between two atoms
2. BThe attraction between two oppositely charged ions
3. COne pair of electrons shared between two atoms
4. DOne electron transferred from one atom to another

For the gas reaction N₂ + 3H₂ ⇌ 2NH₃, what is the effect of increasing the pressure?

1. AThe equilibrium shifts to the left, toward N₂ and H₂
2. BThe NH₃ breaks down completely
3. CThe equilibrium shifts to the right, toward NH₃
4. DThere is no effect on the equilibrium

A plastic block has a density of 0,8 g/cm³. What happens when it is placed in water (density 1,0 g/cm³)?

1. AIt dissolves
2. BIt floats
3. CIt sinks
4. DIt stays suspended halfway down

Nitric acid (HNO₃) reacts with potassium hydroxide (KOH). Which salt forms?

1. APotassium hydride, KH
2. BPotassium nitrate, KNO₃
3. CPotassium nitrite, KNO₂
4. DNitrogen hydroxide, NOH

In the reaction 2Na + Cl₂ → 2NaCl, which substance is the oxidising agent?

1. ANa⁺
2. BNaCl
3. CCl₂
4. DNa

A reaction should produce 2 mol of a product with a molar mass of 30 g/mol, but only 48 g is collected. What is the percent yield?

1. A60%
2. B48%
3. C125%
4. D80%