Užduočių lapas tema Chemija slaugos stojamiesiems egzaminams su atsakymais

What should a student always wear to protect the eyes when working with chemicals?

1. AReading glasses
2. BContact lenses
3. CSafety goggles
4. DSunglasses

What is the name for the attraction of water molecules to each other?

1. AAdhesion
2. BDiffusion
3. CCohesion
4. DOsmosis

How many electrons are shared in a double covalent bond?

1. A6
2. B4
3. C8
4. D2

Water has a high specific heat capacity. How does this help the human body?

1. AIt makes water a poor solvent for salts
2. BIt helps keep body temperature stable
3. CIt makes the blood more acidic
4. DIt allows oxygen to dissolve in water more easily

Which equation shows a combustion reaction?

1. AZn + CuSO₄ → ZnSO₄ + Cu
2. BCaCO₃ → CaO + CO₂
3. CNaOH + HCl → NaCl + H₂O
4. DC₂H₅OH + 3O₂ → 2CO₂ + 3H₂O

What is the oxidation number of sulfur in H₂SO₄?

1. A−2
2. B+2
3. C+4
4. D+6

Burning a match is strongly exothermic, so why does it not catch fire until it is struck?

1. AStriking makes the reaction endothermic
2. BStriking supplies the activation energy to start the reaction
3. CStriking pushes extra oxygen into the chemicals of the match head
4. DThe match must first absorb all its energy from the air

Diamond is extremely hard and has a very high melting point. Which explanation is correct?

1. AIt contains delocalised electrons like a metal
2. BIt is made of separate small molecules with strong forces between them
3. CEach carbon is covalently bonded to four others in a giant network
4. DIt is held together by ionic bonds between C⁺ and C⁻ ions