PH + pOH = 14
pH = 14 - pOH
pH = 14 - 8.7
pH = 5,3
This solution is <u>acidic</u>.
If pH<7 - acidic
If pH=7 - neutral
If pH>7 - basic
The answer would be 16.04.
So,
With addition, we the last digit we keep will be the one which is known for both individual values.
We know 2.13 to the hundredths, but we only know 1 to the ones. Therefore, we will round off in the ones place.
2.13 + 1 = 3.13 (unrounded)
= 3 (rounded)
Hope this helps!
Answer:
6.53g of K₂SO₄
Explanation:
Formula of the compound is K₂SO₄
Given parameters:
Volume of K₂SO₄ = 250mL = 250 x 10⁻³L
= 0.25L
Concentration of K₂SO₄ = 0.15M or 0. 15mol/L
Unknown:
Mass of K₂SO₄ =?
Methods:
We use the mole concept to solve this kind of problem.
>>First, we find the number of moles using the expression below:
Number of moles= concentration x volume
Solving for number of moles:
Number of moles = 0.25 x 01.5
= 0.0375mole
>>Secondly, we use the number of moles to find the mass of K₂SO₄ needed. This can be obtained using the expression below:
Mass(g) = number of moles x molar mass
Solving:
To find the molar mass of K₂SO₄, we must know the atomic mass of each element in the compound. This can be obtained using the periodic table.
For:
K = 39g
S = 32g
O = 16g
Molar mass of K₂SO₄ = (39x2) + 32 + (16x4)
= 78 +32 + 64
= 174g/mol
Using the expression:
Mass(g) = number of moles x molar mass
Mass of K₂SO₄ = 0.0375 x 174 = 6.53g
