Chemia na egzaminy wstępne na pielęgniarstwo: karta pracy z odpowiedziami

Which form of sugar dissolves fastest in a cup of tea?

1. AA large lump of rock sugar
2. BAll forms dissolve at the same rate
3. CA sugar cube
4. DGranulated sugar

What is the formula of methane, the main gas in natural gas?

1. ACH₄
2. BCO₂
3. CCH₂
4. DC₂H₆

Which two substances must be present for iron to rust?

1. ANitrogen and water
2. BHydrogen and oxygen gas only
3. COxygen and water
4. DCarbon dioxide and salt

Why does water boil at a lower temperature at the top of a high mountain?

1. AGravity is weaker, so the molecules escape more easily
2. BThe air pressure is lower, so less vapour pressure is needed to boil
3. CThere is less oxygen dissolved in the water up there
4. DThe air is colder, so the water loses heat and boils sooner

Potassium forms K⁺ ions and sulfur forms S²⁻ ions. What is the name and formula of their compound?

1. APotassium sulfide, K₂S
2. BPotassium sulfate, K₂SO₄
3. CPotassium sulfide, KS₂
4. DPotassium sulfite, KS

How many molecules are in 2 mol of carbon dioxide?

1. A3,01 × 10²³
2. B6,02 × 10²³
3. C1,20 × 10²⁴
4. D2,00 × 10²³

Each C=O bond in carbon dioxide is polar, yet the CO₂ molecule is nonpolar. Why?

1. AThe molecule is linear, so the two bond dipoles cancel out
2. BCarbon and oxygen have the same electronegativity
3. CThe bonds are ionic, not covalent
4. DCarbon has lone pairs that cancel the dipoles

Which approach best reduces a health worker's exposure to ionising radiation?

1. ARely only on wearing gloves
2. BLimit the time near the source, increase the distance and use shielding
3. CStand closer to the source so the job is finished sooner and exposure is shorter
4. DWork faster without any shielding