Answer:
b) 2.0 mol
Explanation:
Given data:
Number of moles of Ca needed = ?
Number of moles of water present = 4.0 mol
Solution:
Chemical equation:
Ca + 2H₂O → Ca(OH)₂ + H₂
now we will compare the moles of Ca and H₂O .
H₂O : Ca
2 : 1
4.0 : 1/2×4.0 = 2.0 mol
Thus, 2 moles of Ca are needed.
Answer:
the answer would be (A.) and (D.).
Explanation:
the reason for that being is because if calcium sulfate is a main component of plaster of paris you would need to find out what is in it that makes it the main component aka (the formula) therefore part of the answer is (A.). The other part of the answer was (D.) because you would need to find the amount of calcium sulfate that contain 12 grams of oxegeon atoms because you finding the answer to that could lead to the answer of what is the main component of plaster of Paris.
The noble gas is Xenon and its molar mass is 131 g/mol.
<h3>What is the molar mass of the noble gas?</h3>
The molar mass of the noble gas is determined as follows;
Let molar mass of unknown gas be M, and mass of gas be m
Density of the noble gas, ρ = 5.8 g/dm³
density = m/V
At STP;
- temperature, T = 273.15 K
- pressure, P = 1 atm
- molar gas constant, R = 0.0821 L.atmK⁻¹mol⁻¹
From ideal gas equation:
PV = nRT
where n = m/M
PV = mRT/M
M = mRT/PV
M = 0.0821 * 273.15 * 5.84/1
Molar mass of the noble gas = 131 g/mol
The noble gas is Xenon which has molar mass approximately equal to 131 g/mol.
Learn more about molar mass at: brainly.com/question/837939
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