True or false. The density of a substance varies with samples of that substance
1 answer:
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Answer:
There is 18.8% lithium by mass in second sample
Explanation:
Both the two samples are pure lithium carbonate. So % lithium by mass will be same in both samples. This can be proved mathematically as follows-
Let's assume weight of first sample is x g
So, 100 g of sample contains 18.8 g of lithium
Hence, x g of sample contains g of lithium
Now, the second sample has weight equal to 2x g
So, 2x g of sample contains g of lithium
So, % lithium by mass in second sample = % = 18.8%
Answer:
the pH of HCOOH solution is 2.33
Explanation:
The ionization equation for the given acid is written as:
Let's say the initial concentration of the acid is c and the change in concentration x.
Then, equilibrium concentration of acid = (c-x)
and the equilibrium concentration for each of the product would be x
Equilibrium expression for the above equation would be:
From given info, equilibrium concentration of the acid is 0.12
So, (c-x) = 0.12
hence,
Let's solve this for x. Multiply both sides by 0.12
taking square root to both sides:
Now, we have got the concentration of
We know that,
pH = -log(0.00465)
pH = 2.33
Hence, the pH of HCOOH solution is 2.33.