उत्तरों सहित नर्सिंग प्रवेश परीक्षाओं के लिए रसायन विज्ञान वर्कशीट

What is an empirical formula?

1. AThe simplest whole-number ratio of atoms in a compound
2. BThe mass of one mole of a compound
3. CThe actual number of each atom in one molecule
4. DA drawing of how the atoms are bonded

Between which kinds of elements do covalent bonds usually form?

1. AA metal and a noble gas
2. BTwo nonmetals
3. CTwo group 1 metals
4. DA metal and a nonmetal

What is an electrolyte?

1. AA substance that dissolves as whole molecules without forming any ions
2. BA metal that conducts electricity as a solid
3. CA substance that forms ions and conducts electricity when dissolved in water
4. DA gas that dissolves in blood

Radioactive iodine (iodine-131) is used to treat some thyroid conditions. Why does it reach the thyroid?

1. AThe thyroid gland takes up iodine to make its hormones
2. BRadiation is always drawn toward the head
3. CIodine is strongly attracted to the metal ions stored in the neck
4. DIodine-131 is not radioactive inside the body

Why is a carbon dioxide extinguisher effective on many fires?

1. ACO₂ is denser than air and pushes oxygen away from the fire
2. BCO₂ is a liquid that soaks into the fuel
3. CCO₂ adds oxygen to cool the flames
4. DCO₂ reacts chemically with the fuel to make it non-flammable

What percentage of the mass of water (H₂O, 18 g/mol) is hydrogen (H = 1 g/mol)?

1. AAbout 5.6%
2. BAbout 89%
3. CAbout 11%
4. DAbout 67%

Using PV = nRT with R = 0.082 L·atm/(mol·K), how many moles of gas are in 24.6 L at 1 atm and 300 K?

1. A2 mol
2. B1 mol
3. C300 mol
4. D0.5 mol

Water is split as 2H₂O → 2H₂ + O₂. What volume of O₂ at STP (0 °C and 1 atm) forms from 2 mol of water?

1. A67.2 L
2. B44.8 L
3. C22.4 L
4. D11.2 L