If the reacted oxygen is 35.1 g.
H2O mass= (35.1+9.8)-29.6
= 19.3g
Answer:
MnSO₄.7H₂O
Explanation:
To solve this question, we need to convert the mass of the dehydrated MnSO₄. The difference between mass of the hydrate and dehydrated compound is the mass of water. With the mass we can find the moles of water and the formula of the hydrate:
<em>Moles MnSO₄ -Molar mass: 151g/mol-:</em>
17.51g * (1mol / 151g) = 0.116 moles
<em>Moles H₂O -Molar mass: 18g/mol-:</em>
32.14g-17.51g = 14.63g * (1mol / 18g) = 0.813 moles
The ratio of moles MnSO₄: Moles H₂O represent the amount of water molecules in the hydrate:
0.813mol / 0.116mol = 7 molecules of water.
The hydrate formula is:
<h3>MnSO₄.7H₂O</h3>
Answer : The mass of calcium chloride is, 116.84 grams
Solution : Given,
Molar mass of calcium chloride,
= 110.98 g/mole
Number of molecules of calcium chloride = 
As we know that,
1 mole of calcium chloride contains
molecules of calcium chloride
or,
1 mole of calcium chloride contains 110.98 grams of calcium chloride
Or, we can say that
As,
molecules of calcium chloride present in 110.98 grams of calcium chloride
So,
molecules of calcium chloride present in
of calcium chloride
Therefore, the mass of calcium chloride is, 116.84 grams
Answer:
0.51M
Explanation:
Given parameters:
Initial volume of NaBr = 340mL
Initial molarity = 1.5M
Final volume = 1000mL
Unknown:
Final molarity = ?
Solution;
This is a dilution problem whereas the concentration of a compound changes from one to another.
In this kind of problem, we must establish that the number of moles still remains the same.
number of moles initially before diluting = number of moles after dilution
Number of moles = Molarity x volume
Let us find the number of moles;
Number of moles = initial volume x initial molarity
Convert mL to dm³;
1000mL = 1dm³
340mL gives
= 0.34dm³
Number of moles = initial volume x initial molarity = 0.34 x 1.5 = 0.51moles
Now to find the new molarity/concentration;
Final molarity =
=
= 0.51M
We can see a massive drop in molarity this is due to dilution of the initial concentration.
Energy(heat) required to raise the temperature of water : 418.6 J
<h3>Further explanation </h3>
Heat can be calculated using the formula:
Q = mc∆T
Q = heat, J
m = mass, g
c = specific heat, joules / g ° C
∆T = temperature difference, ° C / K
Specific heat of water = 4.186 J/g*C.
∆T(raise the temperature) : 10° C
mass = 10 g
Heat required :
