Calculate the H positive from the pH equation: pH equals -log (H positive). This would be 10 to the -6.49. Let's call the acid HA. To calculate Ka in this equation, Ka equals H positive times A- over HA. HA is going to be the 0 0121. So, Ka=(10^-6.49)^2/0.0121. This equals 1.05*10^-13/0.0121. Ka then equals 8.65*10^-12.
144 mL of fluorine gas is required to react with 1.28 g of calcium bromide to form calcium fluoride and bromine gas at STP.
<h3>What is Ideal Gas Law ? </h3>
The ideal gas law states that the pressure of gas is directly proportional to the volume and temperature of the gas.
PV = nRT
where,
P = Presure
V = Volume in liters
n = number of moles of gas
R = Ideal gas constant
T = temperature in Kelvin
Here,
P = 1 atm [At STP]
R = 0.0821 atm.L/mol.K
T = 273 K [At STP]
Now first find the number of moles
F₂ + CaBr₂ → CaF₂ + Br₂
Here 1 mole of F₂ reacts with 1 mole of CaBr₂.
So, 199.89 g CaBr₂ reacts with = 1 mole of F₂
1.28 g of CaBr₂ will react with = n mole of F₂

n = 0.0064 mole
Now put the value in above equation we get
PV = nRT
1 atm × V = 0.0064 × 0.0821 atm.L/mol.K × 273 K
V = 0.1434 L
V ≈ 144 mL
Thus from the above conclusion we can say that 144 mL of fluorine gas is required to react with 1.28 g of calcium bromide to form calcium fluoride and bromine gas at STP.
Learn more about the Ideal Gas here: brainly.com/question/20348074
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Answer:
B
Explanation:
Recall the law of effusion:

Because 5 mol of oxygen was effused in 10 seconds, the rate is 0.5 mol/s.
Let the rate of oxygen be <em>r</em>₁ and the rate of hydrogen be <em>r</em>₂.
The molecular weight of oxygen gas is 32.00 g/mol and the molecular weight of hydrogen gas is 2.02 g/mol.
Substitute and solve for <em>r</em>₂:

Because there are 5 moles of hydrogen gas:

In conclusion, it will take about 2.5 seconds for the hydrogen gas to effuse.
Check: Because hydrogen gas is lighter than oxygen gas, we expect that hydrogen gas will effuse quicker than oxygen gas.
Answer:
4.52 mol/kg
Explanation:
Given data:
Mass of lithium fluoride = 22.1 g
Mass of water = 188 g
Molality = ?
Solution:
Molality:
It is the number of moles of solute into kilogram of solvent.
Formula:
Molality = number of moles of solute / kilogram solvent
Mathematical expression:
m = n/kg
Now we will convert the grams of LiF into moles.
Number of moles = mass/ molar mass
Number of moles = 22.1 g/ 26 g/mol
Number of moles = 0.85 mol
Now we will convert the g of water into kg.
Mass of water = 188 g× 1kg/1000 g = 0.188 kg
Now we will put the values in formula.
m = 0.85 mol / 0.188 kg
m = 4.52 mol/kg
A) Head to tail joining of monomers. :) (confirmed correct answer, I took the test)