Answer:
(a) 3:2; (b) 2:1
Explanation:
The Law of Multiple Proportions states that when two elements A and B combine to form two or more compounds, the masses of B that combine with a given mass of A are in the ratios of small whole numbers.
That is, if one compound has a ratio r₁ and the other has a ratio r₂, the ratio of the ratios r is in small whole numbers.
(a) Ammonia and hydrazine.
In ammonia, the mass ratio of H:N is r₁ = 0.2158/1
In hydrazine, the mass ratio of H:N is r₂ = 0.1439/1
The ratio of the ratios is:
(b) Nitrogen oxides
In nitrogen monoxide, the mass ratio of O:N is r₁ = 1.142/1
In dinitrogen monoxide, the mass ratio of O:N is r₂ = 0.571/1
The ratio of the ratios is:
1.
V = 200 mL (volume)
c = 3 M = 3 mol/L (concentration)
First we convert mL to L:
200 mL = 0.2 L
Then we calculate the moles using the formula: n = V × c = 0.2 L × 3 mol = 0.6 mol
Finally, we just use the molar mass of CaF2 to calculate the actual mass:
molar mass = 78 g/mol
The formula is: m = n × mm (mass = moles × molar mass)
m = 0.6 mol × 78 g/mol = 46.8 g
2.
For this question the steps are exactly like the first question.
V = 50mL = 0.05 L
c = 12 M = 12 mol/L
n = V × c = 0.05 L × 12 mol/L = 0.6 mol
molar mass (HCl) = 36.5 g/mol
m = n × mm = 0.6 mol × 36.5 g/mol = 21.9 g.
3.
The steps for this question are the opposite way.
m(K2CO3) = 250 g
molar mass = 138 g/mol
n = m ÷ mm = 1.81 mol
c = 2 mol/L
V = n ÷ c = 1.81 mol ÷ 2 mol/L = 0.905 L = 905 mL
Answer:
K = 10
Explanation:
Using Hess's law, it is possible to obtain the equilibrium constant, K, of a reaction using K of similar reactions. For example:
<em> If A ⇄ B K = X</em>
B ⇄ A K = 1/X
2A ⇄ 2B K = X².
Thus, if A(g) ⇄ 2B(g) K = 0.010
2B(g) ⇄ A(g) K = 1 / 0.010; K = 100
B(g) ⇄ A(g) K = √100 = 10
<h3>K = 10</h3>
Arsenic, I believe. Metalloids fall in between metals and nonmetals (usually on the bold line separating the two on the periodic table). And since the metalloid in question has four electron shells and five valence electrons in the outermost shell, you can see that this element is arsenic
In each mole of carbon dioxide there will be one mole of O₂.
Let us calculate the moles of carbon dioxide gas present first
The conditions are NTP it means , Temperature = 293 K and P = 1 atm
We will use ideal gas equation
PV= nRT
Where
P = Pressure of gas = 1 atm
V= 112mL=0.112L
R= gas constant =0.0821 L atm /mol K
n = moles = ?
Putting values
moles = 0.00466
Thus moles of carbon dioxide will be 0.00466
The moles of O₂ = 0.00466
