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
The number of grams of NaCl required to make 150.0 ml of a 5.000m solution is 43.875 grams
<u><em>calculation</em></u>
Step 1: calculate moles of NaCl
moles= molarity x volume in liters
volume in liters = 150.0 ml/1000= 0.15 l
moles is= 5.000mol/l x0.15 l =0.75 moles
Step2 : find mass
mass= moles x molar mass
molar mass of NaCl= 23 +35.5 = 58.5 g/mol
mass= 0.75 moles x58.5 g/mol = 43.875 grams
Ions bound together by electrostatic attraction form ionic crystals. ... A simple cubic crystal lattice has ions equally spaced in 3D at 90° angles. Stability of ionic solids depends on lattice energy, which is released in the form of heat when two ions are brought together to form a solid.
Answer:
There are over 10 hazards or more at construction sites ,below are examples
Explanation:
1.Working at height.
2.Moving objects.
3.Slips, trips, and falls.
4.Noise.
5.Hand arm vibration syndrome.
6.Material and manual handling.
7.Collapsing trenches.
8.Asbestos.
9.Electricity.
10.Airborne fibres and materials.
Answer:
The charge on iodine is 2-
