I think is A) made of only one king of atom.
<span>A 240g hydrated sodium sulphide contains 162g of water of crystallisation. What is the correct molecular formula for this compound?
Answer is A
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The atomic density cuases them to be different u can measure the weight mass density # 28 was cut off picture by the way
Answer:
0.534
Explanation:
Mole fraction can be calculated using the formula:
Mole fraction = number of moles of solute ÷ number of moles of solvent and solute (solution).
In this question, solute is dimethyl ether while the solvent is methanol.
Mole (n) = mass (M) ÷ molar mass (MM)
Mole of solute (dimethyl ether) = 148.5 ÷ 46.07
= 3.22moles.
Mole of solvent (methanol) = 90 ÷ 32.04
= 2.81moles.
Total moles of solute and solvent = 3.22 + 2.81 = 6.03moles.
Mole fraction of dimethyl ether = number of moles of dimethyl ether ÷ number of moles of solution (dimethyl ether + methanol)
Mole fraction = 3.22/6.03
= 0.534
Given:
pH is 5.27
Concentration of sol'n 0.013m (weak monoprotic)
Determine H+ concentration:
[H+] = 10^-pH
= 10^-5.27
= 5.37x10^-6
Ka = [H+] [A-] / [HA]
= (5.37x10^-6) * (5.37x10^-6) / (0.013 - 5.37x10^-6)
= 2.22x10^-9