Answer:
Explanation:
The clue of this question is to find the molar mass of the <em>diprotic acid</em> and compare witht the molars masses of the choices' acid to identify the formula of the diprotic acid.
The procedure is:
- Find the number of moles of the base: LiOH
- Use stoichionetry to infere the number of moles of the acid.
- Use the formula molar mass = mass in grams / number of moles, to find the molar mass of the diprotic acid.
- Compare and conclude.
<u>Solution:</u>
<u>1. Number of moles of the base, LiOH:</u>
- M = n / V in liter ⇒ n = M × V = 0.100 M × 40.0 ml × 1 liter / 1,000 ml = 0.004 mol LiOH.
<u>2. Stoichiometry:</u>
Since this a neutralization reaction of a diprotic acid with a mono hydroxide base (LiOH), the mole ratio at the second equivalence point is: 2 mol of base / 1 mole of acid; because each mole of LiOH releases 1 mol of OH⁻, while each mole of diprotic acid releases 2 mol of H⁺.
Hence, 0.004 mol LiOH × 1 mol acid / 2 mol LiOH = 0.002 mol acid.
<u>3. Molar mass of the acid:</u>
- molar mass = mass in grams / number of moles = 0.300 g / 0.002 mol = 150. g/mol
<u>4. Molar mass of the possible diprotic acids:</u>
a. H₂Se: 2×1.008 g/mol + 78.96 g/mol = 80.976 g/mol
b. H₂Te: 2×1.008 g/mol + 127.6 g/mol = 129.616 g/mol
c. H₂C₂O₄ ≈ 2×1.008 g/mol + 2×12.011 g/mol + 4×15.999 g/mol ≈ 90.034 g/mol
d. H₂C₄H₄O₆ = 6×1.008 g/mol + 4×12.011 g/mol + 6×15.999 g/mol = 150.086 g/mol ≈ 150 g/mol.
<u>Conclusion:</u> since the molar mass of H₂C₄H₄O₆ acid is 150 g/mol, you conclude that is the diprotic acid whose 0.300 g were titrated with 40.0 ml of 0.100 M LiOH solution.
<u>Answer:</u>
<u>For a:</u> The volume of the box is 217.5 mL
<u>For b:</u> The volume of the box is 0.2175 L
<u>Explanation:</u>
The box is a type of cuboid.
To calculate the volume of cuboid, we use the equation:
where,
V = volume of cuboid
l = length of cuboid = 10.00 cm
b = breadth of cuboid = 7.25 cm
h = height of cuboid = 3.00 cm
Putting values in above equation, we get:
To convert the volume of cuboid into milliliters, we use the conversion factor:
So,
Hence, the volume of the box is 217.5 mL
To convert the volume of cuboid into liters, we use the conversion factor:
So,
Hence, the volume of the box is 0.2175 L
Answer:
λ = 1×10²⁶m
Explanation:
Given data:
Wavelength of radiation = ?
Frequency of radiation = 3×10⁻¹⁸Hz
Solution:
Formula:
c = f × λ
c = speed of wave = 3×10⁸ m/s
by putting values,
3×10⁸ m/s = 3×10⁻¹⁸Hz × λ
λ = 3×10⁸ m/s / 3×10⁻¹⁸s⁻¹
λ = 1×10²⁶m
Answer:
The answer to your question is: 28°C
Explanation:
Data
mass = 10 g
T1 = 23°C
T2 = ?
Q = 209 joules
Formula
Q = mC(T2 - T1)
T2 = Q/mC + T1
T2 = 209/(10 x 4.182) + 23
T2 = 4.99 + 23
T2 = 27.99 ≈ 28°C