Answer:
iron, graphite,NaCl solution etc are some examples of good conductor of electricity
Ba(OH)2 is an basic solution. It has more OH- ions than H+ ions. pOH should be calculated to find out its pH
The reaction is
Ba(OH)2 ⇒ Ba2+ (aq) + 2 OH-(aq)
One mole barium hydroxide releases 2 moles hydroxide ions.
Use that ratio to calculate molarity (M) of OH- ions [OH-]. The ratio is 1:2.
0.10 M Ba(OH)2 release 2*0.10 M= 0.02 M OH- ions
[OH-]= 0.02
pOH= - log [OH-] = - log 0.02 = 1.7
Thats not the answer! We found pOH of the solution before titration.
pH and pOH relationship is shown by formula of pH+pOH= 14
pH= 14-pOH
pH= 14-1.7= 12.3
The answer is:
a. 0.712 M
b. 0.210 M
c. 0.336 M
Molarity is a measure of the concentration of solute in a solution.
It can be expressed as moles of solute ÷ volume of solution:
c = n ÷V
where:
c - concentration of solute,
n - moles of solute
V - volume of solution
n can be expressed as:
<span>n = m ÷ Mr
</span>where:
<span>n - moles of solute
</span>m - mass of solute
Mr - relative molecular mass
a. We know volume:
V = 289.2 mL = 0.2892 L
We need n and c.
n = m ÷ Mr
m = 15.4 g
Mr (<span>KCl) = 74.55 g/mol
n = </span>15.4 g ÷ <span>74.55 g/mol
n = 0.206 mol</span>
Thus,
c = 0.206 mol ÷ <span>0.2892 L
c = 0.712 mol/L = 0.712 M
</span>b. We know volume:
V = 0.614 L
We need n and c.
n = m ÷ Mr
m = 14.4 g
Mr (CaCl₂<span>) = 110.98 g/mol
n = </span>14.4 g ÷ <span>110.98 g/mol
n = 0.129 mol</span>
Thus,
c = 0.129 mol ÷ <span>0.614 L
c = 0.210 mol/L = 0.210 M
</span>
c. We can use formula:
m₁V₁ = m₂V₂
<span>m₁ = 3 M
</span><span>V₁ = 28 mL= 0.028 L
</span><span>m₂ = ?
</span><span>V₂ = 0.250 L
</span>Thus:
3 M × 0.028 L = m₂× <span>0.250 L
</span> m₂ = 0.336 M
Answer:
we need a picture
Explanation:
but you can ask the question again with one
Answer:
6.707 × 10¹⁷
Explanation:
From the information given:
40 ^ K kütlesi = sütteki K kütlesi × 40 ^ K / 100 kütle yüzdesi
nerede;
sütteki K kütlesi = 1.65 mg of K/mL × 225 mL = 371.25 mg of K
∴
40 ^ K kütlesi = 371.25 × 0.012/100
40 ^ K kütlesi = 0,04455 mg = 4.455 × 10⁻⁵ grams
40 ^ K mol sayısı = 40 ^ K kütlesi / molar kütle
= 4.455 × 10⁻⁵/40
= 1.11375 × 10⁻⁶
Son olarak, 40 ^ K = mol × Avogadro sayısı atomları
= 1.11375 × 10⁻⁶ × 6.022 × 10^23
= 6.707 × 10¹⁷
