Moles (mol) = mass (g) / molar mass (g/mol)
Mass of NaCl = 21.7 g
Molar mass of NaCl = <span>58.4 g/mol
Hence, moles of NaCl = </span>21.7 g / 58.4 g/mol = 0.372 mol
Hence moles of NaCl in the mixture is 0.372 mol.
Let's assume that mixture has only given compounds and free of impurities.
Then, we can present this as a mole percentage.
mole % = (moles of desired substance / Total moles of the mixture) x 100%
Hence,
mole % of NaCl = (moles of NaCl / Total moles of the mixture) x 100%
Total moles of mixture = moles of NaCl + KCl + LiCl
Mass of KCl = 3.74 g
Molar mass of NaCl = 74.6 g/mol
Hence, moles of NaCl = 3.74 g / 74.6 g/mol = 0.050 mol
Mass of NaCl = <span>9.76 g
</span>Molar mass of NaCl = 42.4 g/mol
Hence, moles of NaCl = 9.76 g / 42.4 g/mol = 0.230 mol
Total moles = 0.372 mol + 0.050 mol + 0.230 mol = 0.652 mol
mole % of NaCl = (moles of NaCl / Total moles of the mixture) x 100%
= (0.372 mol / 0.652 mol) x 100%
= 57.06%
Hence, mixture has 57.06% of NaCl as the mole percentage.
Answer:A double convalescent bond is where two pairs of electrons are shared between the atoms rather than just one pair. Two oxygen atoms can both achieve stable structures by sharing two pairs of electrons as in the diagram.
Explanation:
Answer:
Q = -811440 J
Explanation:
Given data:
Mass of oil = 2.76 Kg (2.76× 1000 = 2760 g)
Initial temperature = 191 °C
Final temperature = 23°C
Specific heat capacity of oil = 1.75 J/g.°C
Solution:
Formula:
Q = m.c. ΔT
Q = amount of heat absorbed or released
m = mass of given substance
c = specific heat capacity of substance
ΔT = change in temperature
ΔT = 23°C - 191 °C
ΔT = -168°C
Q = 2760 g ×1.75 J/g.°C ×-168°C
Q = -811440 J
Negative sign show heat is released.
Personal experience from Ag Mech classes-Concrete cools faster than metal.
