Answer:
87.9%
Explanation:
Balanced Chemical Equation:
HCl + NaOH = NaCl + H2O
We are Given:
Mass of H2O = 9.17 g
Mass of HCl = 21.1 g
Mass of NaOH = 43.6 g
First, calculate the moles of both HCl and NaOH:
Moles of HCl: 21.1 g of HCl x 1 mole of HCl/36.46 g of HCl = 0.579 moles
Moles of NaOH: 43.6 g of NaOH x 1 mole of NaOH/40.00 g of NaOH = 1.09 moles
Here you calculate the mole of H2O from the moles of both HCl and NaOH using the balanced chemical equation:
Moles of H2O from the moles of HCl: 0.579 moles of HCl x 1 mole of H2O/1 mole of HCl = 0.579 moles
Moles of H2O from the moles of NaOH: 1.09 moles of HCl x 1 mole of H2O/1 mole of NaOH = 1.09 moles
From the calculations above, we can see that the limiting reagent is HCl because it produced the lower amount of moles of H2O. Therefore, we use 0.579 moles and NOT 1.09 moles to calculate the mass of H2O:
Mass of H2O: 0.579 moles of H2O x 18.02 g of H2O/1 mole of H2O = 10.43 g
% yield of H2O = actual yield/theoretical yield x 100= 9.17 g/10.43 g x 100 = 87.9%
Answer:
2.50 atm
Explanation:
We have 10.4 g of DDT (solute), whose molar mass is 354.50 g/mol. The corresponding moles are:
10.4 g × (1 mol/354.50 g) = 0.0293 mol
The molarity of the solution is:
M = moles of solute / liters of solution
M = 0.0293 mol / 0.286 L
M = 0.102 M
We can find the osmotic pressure (π) using the following pressure.
π = M × R × T
where,
R: ideal gas constant
T: absolute temperature
π = M × R × T
π = 0.102 M × 0.0821 atm.L/mol.K × 298 K
π = 2.50 atm
Answer: The final temperature is equal to
45 Celsius
Explanation:
Explanation:
We have the amount of energy gain
Q
=
m
⋅
c
⋅
Δ
T
=
m
c
Δ
t
where
c
=
4.184
J
/
g
.
C
is the specific heat of water,
m
is the mass of water
⇒
840
=
10
x
4.184
⋅
(
t
−
25
)
t
=
840
10
x
4.184
+
25
=
45
i.e.
45
∘
C
