उत्तरों सहित नर्सिंग प्रवेश परीक्षाओं के लिए रसायन विज्ञान वर्कशीट

What is a molecule?

1. AA mixture of two different elements
2. BThe nucleus of an atom
3. CA single atom with a positive charge
4. DTwo or more atoms held together by covalent bonds

सोडियम क्लोराइड (खाने का नमक) को कौन-सा आबंध साथ बाँधे रखता है?

1. Aसहसंयोजी आबंधन
2. Bआयनिक आबंधन
3. Cहाइड्रोजन आबंधन
4. Dधात्विक आबंधन

What is the melting point of a substance?

1. AThe temperature at which it catches fire
2. BThe temperature at which it dissolves in water
3. CThe temperature at which its liquid turns into a gas
4. DThe temperature at which its solid turns into a liquid

How much heat is needed to raise the temperature of 100 g of water by 10 °C (specific heat of water = 4.18 J/g·°C)?

1. A418 J
2. B41.8 J
3. C4180 J
4. D41,800 J

In the balanced equation __Mg + __HCl → __MgCl₂ + __H₂, what is the coefficient of HCl?

1. A2
2. B1
3. C4
4. D3

How does an antacid tablet relieve heartburn caused by excess stomach acid?

1. AAn acid in it lowers the stomach pH further
2. BIt coats the stomach and stops all acid production
3. CIt turns the acid into a gas that is absorbed
4. DA weak base in it neutralises some of the acid

Marble chips react with hydrochloric acid, giving off CO₂. The gas is produced quickly at first, then more and more slowly. Why does the rate fall?

1. AThe activation energy steadily increases as the reaction goes on
2. BThe CO₂ produced turns back into acid
3. CThe products act as a catalyst that slows the reaction down
4. DThe acid concentration falls as it is used up, so collisions become less frequent

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

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