D = mass / volume
d = 100 g / 100 mL
d = 1.0 g/mL
Answer:
0.85 Molar Na2O
Explanation:
Determine the moles of sodium oxide, Na2O, in 10 grams by dividing by the molar mass of Na2O (61.98 g/mole).
(10 g Na2O)/(61.98 g/mole) = 0.161 moles Na2O.
Molar is a measure of concentration. It is defined as moles/liter. A 1 M solution contains 1 mole of solute per liter of solvent. [200 ml water = 0.2 Liters water.]
In this case, we have 0.161 moles Na2O in 0.200 L of solvent.
(0.161 moles Na2O)/(0.200 L) = 0.85 Molar Na2O
Atoms of oxygen are electronegative and attract the shared electrons in their covalent bonds.
Given:
Iron, 125 grams
T
1 = 23.5 degrees Celsius, T2 =
78 degrees Celsius.
Required:
Heat produced in kilojoules
Solution:
The molar mass of iron is 55.8
grams per mole. SO we need to change the given mass of iron into moles.
Number of moles of iron = 125 g/(55.8
g/mol) = 2.24 moles
<span>
Q (heat) = nRT = nR(T2 = T1)</span>
Q (heat) = 2.24 moles (8.314
Joules per mol degrees Celsius) (78.0 degrees Celsius – 23.5 degrees Celsius)
<u>Q (heat) = 1014.97 Joules or
1.015 kilojoules</u>
<span>This is the amount of heat
produced in warming 125 g f iron.</span>
