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Answer:
Mass = 8 g
Explanation:
Given data:
Mass of MgO formed = 20 g
Mass of oxygen needed = ?
Solution:
Chemical equation:
2Mg + O₂ → 2MgO
Number of moles of MgO:
Number of moles = mass/molar mass
Number of moles = 20 g/ 40 g/mol
Number of moles = 0.5 mol
Now we will compare the moles of MgO and O₂ from balance chemical equation:
MgO : O₂
2 : 1
0.5 : 1/2×0.5 = 0.25 mol
Mass of oxygen required:
Mass = number of moles × molar mass
Molar mass of O₂ is 32 g/mol
Mass = 0.25 mol × 32 g/mol
Mass = 8 g
Answer:
65.2L
Explanation:
Using the general gas equation;
PV = nRT
Where;
P = pressure (atm)
V = volume (Litres)
n = number of moles (mol)
R = gas law constant (0.0821 Latm/molK)
T = temperature (Kelvin)
According to the information provided in this question,
P = 1.631 atm
V = ?
n = 4.3 moles
T = 28°C = 28 + 273 = 301K
Using PV = nRT
V = nRT/P
V = 4.3 × 0.0821 × 301 ÷ 1.631
V = 106.26 ÷ 1.631
V = 65.15
Volume of the gas = 65.2L
Answer : The correct option is, 0.961 g/ml
Solution : Given,
Mass of sample = 35.4 g
Volume of sample = 36.82 ml
Formula used :
Now put all the given values in this formula, we get the density of the sample.
Therefore, the density of the sample is, 0.961 g/ml