Phiếu bài tập Hóa học cho kỳ thi đầu vào điều dưỡng có đáp án

At sea level, at what temperature does pure water freeze?

1. A100 °C (212 °F)
2. B0 °C (32 °F)
3. C−32 °C (−26 °F)
4. D32 °C (90 °F)

Which two substances must be present for iron to rust?

1. AHydrogen and oxygen gas only
2. BNitrogen and water
3. COxygen and water
4. DCarbon dioxide and salt

Sự chuyển trực tiếp từ thể rắn sang thể khí gọi là gì?

1. ASự ngưng tụ
2. BSự kết tủa từ pha khí (ngưng kết)
3. CSự nóng chảy
4. DSự thăng hoa

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

1. A5%
2. B75%
3. C25%
4. D133%

Why does the vapour pressure of a liquid increase as it is heated?

1. AThe liquid's volume decreases and squeezes out vapour
2. BThe attractions between the molecules become stronger
3. CMore molecules have enough energy to escape into the gas phase
4. DThe molecules become heavier and press harder on the surface

Water can act as an acid in some reactions and as a base in others. What is such a substance called?

1. AAmphoteric
2. BSaturated
3. CIsotonic
4. DNeutral

An element has the electron arrangement 2, 8, 8, 2. Where is it on the periodic table?

1. AGroup 8, period 2
2. BGroup 4, period 2
3. CGroup 2, period 2
4. DGroup 2, period 4

Ethanol (CH₃CH₂OH) and dimethyl ether (CH₃OCH₃) have the same formula, C₂H₆O, but ethanol boils at a much higher temperature. Why?

1. AEthanol molecules are heavier than dimethyl ether molecules
2. BEthanol has more carbon atoms
3. CDimethyl ether is ionic and ethanol is covalent
4. DEthanol has an O–H group, so its molecules form hydrogen bonds with each other