Answer:
Mass = 2.77 g
Explanation:
Given data:
Mass of HCl = 2 g
Mass of CaCl₂ produced = ?
Solution:
Chemical equation:
2HCl + Ca → CaCl₂ + H₂
Number of moles of HCl:
Number of moles = mass / molar mass
Number of moles = 2 g/ 36.5 g/mol
Number of moles = 0.05 mol
now we will compare the moles of HCl with CaCl₂.
HCl : CaCl₂
2 : 1
0.05 : 1/2×0.05 = 0.025 mol
Mass of CaCl₂:
Mass = number of moles × molar mass
Mass = 0.025 mol × 110.98 g/mol
Mass = 2.77 g
I believe it was decomposition reaction
Answer:
6.53g of K₂SO₄
Explanation:
Formula of the compound is K₂SO₄
Given parameters:
Volume of K₂SO₄ = 250mL = 250 x 10⁻³L
= 0.25L
Concentration of K₂SO₄ = 0.15M or 0. 15mol/L
Unknown:
Mass of K₂SO₄ =?
Methods:
We use the mole concept to solve this kind of problem.
>>First, we find the number of moles using the expression below:
Number of moles= concentration x volume
Solving for number of moles:
Number of moles = 0.25 x 01.5
= 0.0375mole
>>Secondly, we use the number of moles to find the mass of K₂SO₄ needed. This can be obtained using the expression below:
Mass(g) = number of moles x molar mass
Solving:
To find the molar mass of K₂SO₄, we must know the atomic mass of each element in the compound. This can be obtained using the periodic table.
For:
K = 39g
S = 32g
O = 16g
Molar mass of K₂SO₄ = (39x2) + 32 + (16x4)
= 78 +32 + 64
= 174g/mol
Using the expression:
Mass(g) = number of moles x molar mass
Mass of K₂SO₄ = 0.0375 x 174 = 6.53g
By measuring them, by monitoring them, or by separating them.
When given percents for an empirical formula problem, first consider all the percents as grams.
58.82% carbon —> 58.82 g carbon
27.45% nitrogen —> 27.45 g nitrogen
13.73% hydrogen —> 13.73 g hydrogen
Then convert the grams of all the elements to moles, based on their molar masses.
Carbon - 58.82 g / 12.01 g/mol = 4.898 mol carbon
Nitrogen - 27.45 g / 14.01 g/mol = 1.959 mol nitrogen
Hydrogen - 13.73 g / 1.008 g/mol = 13.62 mol hydrogen
Then divide all of the mole numbers by the smallest number of moles, which is in this case, the 1.959 mol of nitrogen.
Carbon - 4.898 / 1.959 = 2.5
Nitrogen - 1.959 / 1.959 = 1
Hydrogen - 13.62 / 1.959 = 7
You want whole numbers for all of your mole numbers, so multiply all of them by 2, since 2.5 isn’t a whole number.
Final answer: C5N2H14
