ใบงาน เคมีสำหรับข้อสอบเข้าพยาบาล พร้อมเฉลย

ข้อใดต่อไปนี้เป็นสารประกอบ

1. Aคาร์บอนไดออกไซด์ (CO₂)
2. Bเหล็ก (Fe)
3. Cแก๊สออกซิเจน (O₂)
4. Dฮีเลียม (He)

Which element exists naturally as diatomic molecules (two atoms joined together)?

1. AOxygen
2. BHelium
3. CSodium
4. DIron

Which state of matter has neither a fixed shape nor a fixed volume?

1. ASolid
2. BGas
3. CCrystal
4. DLiquid

To which family of organic compounds does ethanol, C₂H₅OH, belong?

1. ACarboxylic acids
2. BAlkanes
3. CAlcohols
4. DEsters

In the ideal gas law, PV = nRT, what does n stand for?

1. AThe number of molecules of gas
2. BThe density of the gas
3. CThe number of atoms per molecule
4. DThe number of moles of gas

วัตถุมีมวล 50 g และปริมาตร 20 cm³ มีความหนาแน่นเท่าใด

1. A0.4 g/cm³
2. B70 g/cm³
3. C2.5 g/cm³
4. D1000 g/cm³

Steel can be protected from rusting by coating it with zinc (galvanising). Why does the steel stay protected even if the zinc coating is scratched?

1. AZinc absorbs all the water from the air
2. BZinc turns the iron into a noble metal
3. CZinc is less reactive than iron, so it pushes oxygen and water away from the iron
4. DZinc is more reactive than iron, so it corrodes instead of the iron

Frying an egg turns the clear egg white solid and white. What happens to the proteins?

1. AThey are converted into fats
2. BThey are denatured: their shape changes, but the peptide bonds stay intact
3. CThey are burned to carbon dioxide and water
4. DThey are hydrolysed, so the peptide bonds break into separate amino acids