Answer: D. Potassium bromide
10 seconds = 8grams
then just divide by 2 another 4 times...
= 0.5grams after 50 seconds
Answer:
B. Are fixed within electron orbitals
Explanation:
Electrons are found in the energy levels
Answer: 126.1 grams of are needed to make 5.3 L of 0.25 M solution
Explanation:
Molarity of a solution is defined as the number of moles of solute dissolved per liter of the solution.
To calculate the mass of solute for given molarity, we use the equation:
Thus 126.1 grams of are needed to make 5.3 L of 0.25 M solution
Answer:
13.20
Explanation:
Step 1: Calculate the moles of Ba(OH)₂
The molar mass of Ba(OH)₂ is 171.34 g/mol.
0.797 g × 1 mol/171.34 g = 4.65 × 10⁻³ mol
Step 2: Calculate the molar concentration of Ba(OH)₂
Molarity is equal to the moles of solute divided by the liters of solution.
[Ba(OH)₂] = 4.65 × 10⁻³ mol/60 × 10⁻³ L = 0.078 M
Step 3: Calculate [OH⁻]
Ba(OH)₂ is a strong base according to the following equation.
Ba(OH)₂ ⇒ Ba²⁺ + 2 OH⁻
The concentration of OH⁻ is 2/1 × 0.078 M = 0.16 M
Step 4: Calculate the pOH
pOH = -log OH⁻ = -log 0.16 = 0.80
Step 5: Calculate the pH
We will use the following expression.
pH + pOH = 14
pH = 14 - 0.80 = 13.20
