Answer:
251 g of compound contain 2.39 moles.
Explanation:
Given data:
mass of compound Al(CN)3 = 251 g
moles = ?
Solution:
First of all we will calculate the molar mass of given compound.
molar mass of Al(CN)3 = 26.98 + (26 × 3)
molar mass of Al(CN)3 = 105 g/mol
Formula:
number of moles = mass/ molar mass
number of moles = 251 g / 105 g/mol
number of moles = 2.39 mole
Answer:
448mL AgNO3
Explanation:
M x V
n = 0.230 x .045 = 0.01
2AgNO3 + Na2S --> Ag2S+2NaNO3
1 mol Ag2S --> 2 moles AgNO3
.01 mol Ag2S --> ? moles AgNO3
.01x2/1=.02 moles AgNO3
Moles to L conversion is multiplying by 22.4L so we do .02 x 22.4=0.448L
Then we convert to mL so we multiply by 1000 (1000 x 0.448)
448mL AgNO3
There you go friend, good luck with chemistry :)
Answer:
70.0 %
Explanation:
Step 1: Given data
- Mass of nitrogen (mN): 74.66 g
- Mass of the compound (mNxOy): 250 g
Step 2: Calculate the mass of oxygen (mO) in the compound
The mass of the compound is equal to the sum of the masses of the elements that form it.
mNxOy = mN + mO
mO = mNxOy - mN
mO = 250 g - 74.66 g = 175 g
Step 3: Determine the percent composition of oxygen in the sample
We will use the following expression.
%O = mO / mNxOy × 100%
%O = 175 g / 250 g × 100% = 70.0 %
Answer:
CHEMICAL CHANGE
Explanation:
Chemical reaction is synonymous to a chemical change. A chemical change is one which is not easily reversed and in which a new substance is formed.
The reactants are converted to products by the rearrangement of the constituent atoms to form a different compound.
Examples include burning of fuel, smelting of iron.
Physical change is different from chemical change as it involves a change of state or phase and the chemical properties of its constitients elements are intact. Unlike in chemical change where there is a change in the chemical properties of the new products formed
Answer:
pH = 7.46.
Explanation:
- The ionization of water is given by the equation :
<em>H₂O(l) ⇄ H⁺(aq) + OH⁻(aq),</em>
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- The equilibrium constant (Kw) expression is:
<em>Kw = [H⁺][OH⁻] = 0.12 x 10⁻¹⁴. </em>
<em></em>
in pure water and neutral aqueous solution, [H⁺] = [OH⁻]
So, Kw = [H⁺]²
∴ 0.12 x 10⁻¹⁴ = [H⁺]²
∴ [H⁺] = 3.4 x 10⁻⁸ M.
∵ pH = - log [H⁺]
pH = - log (3.4 x 10⁻⁸) = 7.46.
