Answer:
[HF]₀ = 0.125M
Explanation:
NaOH + HF => NaF + H₂O
Adding 20ml of 0.200M NaOH into 25ml of HF solution neutralizes 0.004 mole of HF leaving 0.004 mole NaF in 0.045L with 0.001M H⁺ at pH = 3. This is 0.089M NaF and 0.001M HF remaining.
=> 45ml of solution with pH = 3 and contains 0.089M NaF from titration becomes a common ion problem.
HF ⇄ H⁺ + F⁻
C(eq) [HF] 10⁻³M 0.089M (<= soln after adding 20ml 0.200M NaOH)
Ka = [H⁺][F⁻]/[HF]₀ => [HF]₀ = [H⁺][F⁻]/Ka
[HF]₀ = (0.001)(0.089)/(7.1 x 10⁻⁴) M = 0.125M
Answer:
Electrons
Explanation:
Because the nucleas is In the middle and the Electrons surround it
74.62 g of magnesium oxide is formed from 45.00 g magnesium so 74.62-45.00= 29.62 g of oxygen is consumed or in other words a new compound is formed in the burning of magnesium in oxygen with a heavier mass than the pure magnesium.
Answer:
992.302 K
Explanation:
V(rms) = 750 m/s
V(rms) = √(3RT / M)
V = velocity of the gas
R = ideal gas constant = 8.314 J/mol.K
T = temperature of the gas
M = molar mass of the gas
Molar mass of CO₂ = [12 + (16*2)] = 12+32 = 44g/mol
Molar mass = 0.044kg/mol
From
½ M*V² = 3 / 2 RT
MV² = 3RT
K = constant
V² = 3RT / M
V = √(3RT / M)
So, from V = √(3RT / M)
V² = 3RT / M
V² * M = 3RT
T = (V² * M) / 3R
T = (750² * 0.044) / 3 * 8.314
T = 24750000 / 24.942
T = 992.302K
The temperature of the gas is 992.302K
Note : molar mass of the gas was converted from g/mol to kg/mol so the value can change depending on whichever one you use.
Answer: X2Y3
Explanation: I had the same question ;) (and got it right)