Answer:
The first one
Explanation:
- K must be calculated with the concentrations AT equilibrium, not initial concentrations.
The balanced equation between the
and
is:

Formula of molarity is:


Substituting the values,

So, number of moles of
is
.
From the balanced equation it is clear that for 1 mole of
, 2 moles of
are required.
Hence, 0.21 mole of
= 
Molar mass of
= 
So, the mass of
= 
Answer:
0.075
Explanation:
First obtain the mean of the measurement;
Mean = 10.15 + 9.95 + 9.99 + 10.02/4 = 10.03
Then obtain d^2= (mean-score)^2 for each score;
(10.15-10.03)^2 = 0.0144
(9.95-10.03)^2 = 0.0064
(9.99-10.03)^2 = 0.0016
(10.02-10.03)^2= 0.0001
∑d^2= 0.0144 + 0.0064 + 0.0016 + 0.0001
∑d^2= 0.0225
Variance = ∑d^2/N = 0.0225/4 = 0.005625
Standard deviation= √0.005625
Standard deviation= 0.075
Answer:
20% of phosphorus
Explanation:
A fertilizer is used to improve the fertility of soils. Most fertilizers contains the element nitrogen, phosphorus and potassium.
They are often designated NPK fertilizers.
Now we know that the numbers 10-20-20 depicts the nitrogen-phosphorus and potassium content of the fertilizer.
From the designation,
The actual percentage is 20% of phosphorus.
10% of nitrogen
20% of potassium
First convert celcius to Kelvin.
20 + 273 = 293K
31 + 273 = 304K
Now we can set up an equation based on the information we have.
V1 = 5
P1 = 365
T1 = 293
V2 = 5
P1 = x
T2 = 304
The equation be: 
Now just solve.
1825/293 = 5x/304
Cross multiply.
554800 = 1465x
Divide both sides by 1465
x = 378.7030717 which can then be rounded to 378.7 mmHg