Answer:

Explanation:
Given the moles, we are asked to find the mass of a sample.
We know that the molar mass of methanol is 32.0 grams per mole. We can use this number as a fraction or ratio.

Multiply by the given number of moles, which is 2.0

The moles of methanol will cancel each other out.

The denominator of 1 can be ignored.

Multiply.

There are 64 grams of methanol in the sample.
Can be produced from a variety of material, including , it’s at a C or D.
To answer the problem given:
|0.53−4.0| / 4.0 * 100%
= 3.47 / 4.0 * 100%
= 87%
The maximum theoretical percent recovery from the
crystallization of 4.0 g of acetanilide from 100 ml of water is 87%. I
am hoping that this answer has satisfied your query and it will be able to help
you in your endeavor, and if you would like, feel free to ask another question.
Explanation:
Half life is simply the amount of time it takes for half of a substance to decompose.
Options;
- Carbon-14 has a half-life of 5,730 years. A 30 gram sample will be 10 grams after 5,730 years. This is incorrect. After 5730 years, 15g of the sample ought to remain.
- Nickel-59 has a half-life of 76,000 years. A sample would go through 3 half-lives in 228,000 years. This is correct. 3 * 76000 = 228,000
- Hafnium-182 has a half-life of 9 million years. A 38 gram sample would be 4.75 grams in 27 million years. This is incorrect. Mass after 3 half lives (27/9) = 9.5 (38 / 2 / 2)
- Iron-60 has a half-life of 1.5 million years. In 6 million years a 40 gram sample would be reduced to 10 grams. This is incorrect. Mass after 4 half lives (6 / 1.5) = 2.5 gram (40 / 2 / 2 /2 / 2)
- Lead-202 has a half-life of 52,500 years. The original sample must have been 120 grams if you have a 60 gram sample after 105,000 years. This is incorrect. Original sampe = 240 gram. So after 2 half lives (105,000/52500), mass left = 60 (240 / 2 /2)