Answer:
0.17325 moles per liter per second
Explanation:
For a first order reaction;
in[A] = in[A]o - kt
Where;
[A]= concentration at time t
[A]o = initial concentration
k= rate constant
t= time taken
ln0.5 =ln1 - 2k
2k = ln1 - ln0.5
k= ln1 - ln0.5/2
k= 0 -(0.693)/2
k= 0.693/2
k= 0.3465 s-1
Rate of reaction = k[A]
Rate = 0.3465 s-1 × 0.50 mol/L
Rate = 0.17325 moles per liter per second
Answer:
A. the atomic number
Explanation:
It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth.
Answer:
0.159 M
Explanation:
convert from mL to L then use the equation:
M1V1 = M2V2
rearrange to find M2


The freezing point of a solution containing 5. 0 grams of KCl and 550.0 grams of water is - 0.45°C
Using the equation,
Δ
= i
m
where:
Δ
= change in freezing point (unknown)
i = Van't Hoff factor
= freezing point depression constant
m = molal concentration of the solution
Molality is expressed as the number of moles of the solute per kilogram of the solvent.
Molal concentration is as follows;
MM KCl = 74.55 g/mol
molal concentration =
molal concentration = 0.1219m
Now, putting in the values to the equtaion Δ
= i
m we get,
Δ
= 2 × 1.86 × 0.1219
Δ
= 0.4536°C
So, Δ
of solution is,
Δ
= 0.00°C - 0.45°C
Δ
= - 0.45°C
Therefore,freezing point of a solution containing 5. 0 grams of KCl and 550.0 grams of water is - 0.45°C
Learn more about freezing point here;
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