Why is potasium oxide not used to investigate property of hydrogen gas
1 answer:
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Answer:
Explanation:
From the given information:
mass of silver chloride AgCl = 11.89 g
molar mass of AgCl = 143.37 g/mol
We know that:
number of moles = mass/molar mass
∴
number of moles of AgCl = 11.89 g/ 143.37 g/mol
number of moles of AgCl = 0.0829 mol
The chemical equation for the mineral called trona is:
when being reacted with hydrochloric acid, we have:
One mole of NaCl formed from one mole of trona sample = 0.0829 moles of AgCl
i.e. 0.0829 moles of NaCl can be formed from AgCl
mass of trona sample = number of moles × molar mass
mass of trona sample = 0.0829 × 226
mass of trona sample = 18.735 g
The mass in the percentage of NaHCO₃ = mass of NaHCO₃/ mass of trona
The mass in the percentage of NaHCO₃ = 6.93/18.735
The mass in the percentage of NaHCO₃ = 0.36989
The mass in the percentage of NaHCO₃ = 36.99%
Nonetheless, a 6.78 g samples manufactured from sodium carbonate in pure 100%
∴
6.78 g sample manufactured from Na₂CO₃ is purer.
Answer:
Explanation:
We need to use the formula for heat of vaporization.
Identify the variables.
- The heat absorbed by the evaporating water is the <u>latent heat of vaporization. </u>For water, that is 2260 Joules per gram.
- Q is the energy, in this problem, 50,000 Joules.
- m is the mass, which is unknown.
Substitute the values into the formula.
We want to find the mass. We must isolate the variable, m.
m is being multiplied by 2260 J/g. The inverse operation of multiplication is division. Divide both sides by 2260 J/g.
Divide. Note that the Joules (J) will cancel each other out.
Round to the nearest whole number. The 1 in the tenth place tells us to leave the number as is.
The mass is about 22 grams, so choice B is correct.