Werkblad Scheikunde voor toelatingsexamens verpleegkunde met antwoorden

What is the change from a gas to a liquid called?

1. ACondensation
2. BEvaporation
3. CFreezing
4. DSublimation

What is the half-life of a radioactive isotope?

1. AThe time taken for half of the radioactive atoms in a sample to decay
2. BThe time taken for the mass of a sample to double in size
3. CHalf the number of protons in the nucleus
4. DHalf the time it takes for all the atoms to decay

What is the formula of sulfuric acid?

1. AHCl
2. BHNO₃
3. CH₂SO₃
4. DH₂SO₄

What is the oxidation number of an element in its uncombined (elemental) form, such as Fe or O₂?

1. A0
2. B−1
3. CIt equals the group number
4. D+1

A reaction has a theoretical yield of 20 g, but only 15 g of product is collected. What is the percent yield?

1. A25%
2. B5%
3. C75%
4. D133%

How is 0,00045 written in scientific notation?

1. A4,5 × 10⁴
2. B4,5 × 10⁻³
3. C4,5 × 10⁻⁴
4. D4,5 × 10⁻⁵

A compound has the empirical formula CH₂ and a molar mass of 42 g/mol (C = 12, H = 1). What is its molecular formula?

1. AC₄H₈
2. BC₃H₆
3. CC₂H₄
4. DCH₂

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. BOxygen is heavier, so it all sinks to sea level
3. CThe total air pressure is lower, so the partial pressure of oxygen is lower
4. DCold air contains no oxygen