Answer:
b
Explanation:
b because it's a physical change
Answer:
1. 35 mg of H₃PO₄
2. 27 mol AlF₃; 82 mol F⁻
3. 300 mL of stock solution.
Explanation:
1. Preparing a solution of known molar concentration
Data:
V = 80 mL
c = 4.5 × 10⁻³ mol·L⁻¹
Calculations:
(a) Moles of H₃PO₄
Molar concentration = moles of solute/litres of solution
c = n/V
n = Vc = 0.080L × (4.5 × 10⁻³ mol/1 L) = 3.60 × 10⁻⁴ mol
(b) Mass of H₃PO₄
moles = mass/molar mass
n = m/MM
m = n × MM = 3.60 × 10⁻⁴ mol × (98 g/1 mol) = 0.035 g = 35 mg
(c) Procedure
Dissolve 35 mg of solid H₃PO₄ in enough water to make 80 mL of solution,
2. Moles of solute.
Data:
V = 4900 mL
c = 5.6 mol·L⁻¹
Calculations:
Moles of AlF₃ = cV = 4.9 L AlF₃ × (5.6 mol AlF₃/1L AlF₃) = 27 mol AlF₃
Moles of F⁻ = 27 mol AlF₃ × (3 mol F⁻/1 mol AlF₃) = 82 mol F⁻.
3. Dilution calculation
Data:
V₁= 750 mL; c₁ = 0.80 mol·L⁻¹
V₂ = ? ; c₂ = 2.0 mol·L⁻¹
Calculation:
V₁c₁ = V₂c₂
V₂ = V₁ × c₁/c₂ = 750 mL × (0.80/2.0) = 300 mL
Procedure:
Measure out 300 mL of stock solution. Then add 500 mL of water.
Answer:
option 1. Two substances in a mixture differ in density and particle size. These properties can be used to separate the substances. These properties can be manipulated in order to have a better separation between the two substances.
Explanation:
<u>Answer:</u> The expression for equilibrium constant in terms of concentration is ![K_c=[CO_2]](https://tex.z-dn.net/?f=K_c%3D%5BCO_2%5D)
<u>Explanation:</u>
Equilibrium constant in terms of concentration is defined as the ratio of concentration of products to the concentration of reactants each raised to the power their stoichiometric coefficients. It is represented by 
For a general chemical reaction:
The is written as:
![K_{c}=\frac{[C]^c[D]^d}{[A]^a[B]^b}](https://tex.z-dn.net/?f=K_%7Bc%7D%3D%5Cfrac%7B%5BC%5D%5Ec%5BD%5D%5Ed%7D%7B%5BA%5D%5Ea%5BB%5D%5Eb%7D)
The concentration of pure solids and pure liquids are taken as 1.
For the given chemical reaction:
The expression for is:
![K_{c}=\frac{[MgO][CO_2]}{[MgCO_3]}](https://tex.z-dn.net/?f=K_%7Bc%7D%3D%5Cfrac%7B%5BMgO%5D%5BCO_2%5D%7D%7B%5BMgCO_3%5D%7D)
In the above expression, magnesium oxide and magnesium carbonate will not appear because they are present in solid state.
So, the expression for 
becomes:
![K_{c}=[CO_2]](https://tex.z-dn.net/?f=K_%7Bc%7D%3D%5BCO_2%5D)
Hence, the equilibrium constant for the reaction is given above.
Answer:
847 mL
Explanation:
Step 1: Find conversion
1 L = 1000 mL
Step 2: Use Dimensional Analysis
<em>We see that Liters and Liters cancel out, so we simply multiply.</em>
847 mL
