1. Magnesium chloride is 25.5% magnesium. What mass of magnesium could be recovered by the decomposition of 25.5g of magnesium chloride?
a) 25.5g
b) 35.0g
c) 6.50g
d) 8.94g
2. Zinc oxide contains 80.3% zinc. What size sample would contain 5.35g of zinc?
a) 6.66g
b) 27.2g
c) 4.30g
d) 11.0g
3. To heat 60.0g of water from 30.0 degrees Celsius to 50.0 degrees Celsius requires:
a) 5.02 kJ
b) 7.53 kJ
c) 12.6 kJ
d) 6.28 kJ
4. 3.17g of sodium combines with chlorine to form 8.00g of sodium chloride. What is the mass of chlorine in this sample of sodium chloride?
a) 3.17g
b) 4.83g
c) 8.00g
d) 11.17g
5.True or False:
Physical properties describe the ability of a substance to form new substances.
When you give the answer will you please give an explanation so that I can understand it too? Thank you!
a) 25.5g
b) 35.0g
c) 6.50g
d) 8.94g
2. Zinc oxide contains 80.3% zinc. What size sample would contain 5.35g of zinc?
a) 6.66g
b) 27.2g
c) 4.30g
d) 11.0g
3. To heat 60.0g of water from 30.0 degrees Celsius to 50.0 degrees Celsius requires:
a) 5.02 kJ
b) 7.53 kJ
c) 12.6 kJ
d) 6.28 kJ
4. 3.17g of sodium combines with chlorine to form 8.00g of sodium chloride. What is the mass of chlorine in this sample of sodium chloride?
a) 3.17g
b) 4.83g
c) 8.00g
d) 11.17g
5.True or False:
Physical properties describe the ability of a substance to form new substances.
When you give the answer will you please give an explanation so that I can understand it too? Thank you!
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1) This is simple computation: 25.5 g * 25.5% = 6.50 g
2) This one is the same, plus a little algebra: x * 80.3% = 5.35 g
x = 5.35 g / 80.3%
x = 6.66 g
3) Specific heat is the physical property that determines how much energy is required to increase the temperature of a unit of a given substance by one degree. The specific heat of water is 4.186 joule/(gram °C) (first link)
so 60 g of water * (50-30) °C * 4.186 joule/(gram °C) =
60 * 20 * 4.186 = 5.02 kJ
4) If they give you the weight of the compound and the mass of one of the two components, you can subtract to find the mass of the other.
8.00 g NaCl - 3.17 g Na = 4.83 g Cl
5) Based on the second and third links, I would say false. The ability of a substance to form new substances is a chemical property.
2) This one is the same, plus a little algebra: x * 80.3% = 5.35 g
x = 5.35 g / 80.3%
x = 6.66 g
3) Specific heat is the physical property that determines how much energy is required to increase the temperature of a unit of a given substance by one degree. The specific heat of water is 4.186 joule/(gram °C) (first link)
so 60 g of water * (50-30) °C * 4.186 joule/(gram °C) =
60 * 20 * 4.186 = 5.02 kJ
4) If they give you the weight of the compound and the mass of one of the two components, you can subtract to find the mass of the other.
8.00 g NaCl - 3.17 g Na = 4.83 g Cl
5) Based on the second and third links, I would say false. The ability of a substance to form new substances is a chemical property.