Answer:
CH2N2
Explanation:
To find the molecular formula, we must first find the empirical formula as follows:
28.57% C - 28.57g of Carbon
4.80% H - 4.80g of Hydrogen
66.64% N - 66.64g of Nitrogen
Next, we convert this mass values to mole by dividing by their respective atomic mass.
C = 28.57/12 = 2.38mol
H = 4.80/1 = 4.80mol
N = 66.64/14 = 4.76mol
Next, we divide each mole value by the smallest mole value (2.38mol)
C = 2.38mol ÷ 2.38 = 1
H = 4.80mol ÷ 2.38 = 2.01
N = 4.76mol ÷ 2.38 = 2
The empirical ratio of C, H and N is therefore 1:2:2. Hence, the empirical formula is CH2N2
To calculate the molecular formula;
(CH2N2)n = 42.04 g/mol
{12 + 1(2) + 14(2)}n = 42.04
{12 + 2 + 28}n = 42.04
{42}n = 42.04
n = 42.04/42
n = 1.00009
Since n = 1, molecular formula is CH2N2
28.01 g/mol is the answer for carbon monoxide (CO)
Answer: 2.223
Explanation:
HClO4, also known as perchloric acid, is a very strong. This means we can assume that complete dissociation occurs.
This means that:
[H+] = [HClO4] = <span>0.00598
pH = -log[H+]
pH = -log[</span><span>0.00598] = 2.223
Note: The base of the log is 10 (conventionally we don't write the base if it is 10)</span>
Answer:
a) 231.9 °C
b) 100% Sn
c) 327.5 °C
d) 100% Pb
Explanation:
This is a mixture of two solids with different fusion point:
<u>Given that Sn has a lower fusion temperature it will start to melt first at that temperature. </u>
So the first liquid phase forms at 231.9 °C and because Pb starts melting at a higher temperature, that phase's composition will be 100% Sn.
The mixture will be completely melted when you are a the higher melting temperature of all components (in this case Pb), so it will all in liquid phase at 327.5 °C.
At that temperature all Sn was already in liquid state and, therefore, the last solid's composition will be 100% Pb.
