Answer:
The pH is 13,00 and the solution is basic.
Explanation:
<em> </em>The pH indicates the acidity or basicity of a substance. PH values between 0 and less than 7 indicate acidic solutions, 7 neutral and higher than 7 to 14 basic. It is calculated as
pH = -log (H 30+)
Both pH and pOH have a relationship to belonging to the same aqueous solution: the expression of the Kwater (ionic product of the water Kw) is used:
[H3O ^ +]x [OH ^ -] = 1x 10 ^ -14
[H3O ^ +]x [1.0 10-1]=1x 10 ^ -14
[H3O ^ +]= 1x 10 ^ -14/1.0 10-1M= <em>1.0 10-13 M</em>
pH = -log (H 30+)= -log (1.0 10-13 M)= <em>13, 00</em>
As the pH value is higher than 7, it corresponds to a basic substance.
The answer is (3) 3. The calculation rule of significant figures is when multiplication and division, the significant figures of result is equal to the least of the numbers involved. The significant figure of 2.70 and 80.01 is 3 and 4.
Explanation:
when water is boiling and when u cover it and increase the pressure it causes the increase in rate of condensation.
The initial mass of sodium hydroxide is 3.3 g (answer C)
<u><em>calculation</em></u>
Step 1 : find the moles of iron (ii) hydroxide ( Fe(OH)₂
moles = mass÷ molar mass
from periodic table the molar mass of Fe(OH)₂ = 56 + [16 +1]2 = 90 g/mol
moles is therefore = 3.70 g÷ 90 g/mol = 0.041 moles
Step 2: use the mole ratio to calculate the moles of sodium hydroxide (NaOH)
from given equation NaOH : Fe(OH)₂ is 2 :1
therefore the moles of NaOH = 0.041 x 2 = 0.082 moles
Step 3: find mass of NaOH
mass = moles x molar mass
from the periodic table the molar mass of NaOH = 23 +16 +1 = 40 g/mol
mass = 0.082 moles x 40 g/mol = 3.3 g ( answer C)
