What you have to do is find a periodic table and add the mass of each atom that the compound is made of.
Ca= 40.1
O= 16.0
H= 1.01
keep in mind that you have to also account for how many atoms of each there are in the molecule. for example, in Ca(OH)2, there are one Ca, two O and two H
so the molar mass of Ca(OH)2= 40.1 + (2 x 16.0) + (2 x 1.01)= 74.12 g/mol
Answer:
Explanation:
Given that:
The Half-life of 
= 
is less than that of 
Although we are not given any value about the present weight of .
So, consider the present weight in the percentage of to be y%
Then, the time elapsed to get the present weight of = 
Therefore;
here;
= Number of radioactive atoms relating to the weight of y of
Thus:
--- (1)
However, Suppose the time elapsed from the initial stage to arrive at the weight of the percentage of to be = 
Then:
---- (2)
here;
= Number of radioactive atoms of relating to 3.0 a/o weight
Now, equating equation (1) and (2) together, we have:
replacing the half-life of =
( since 
)
∴
The time elapsed signifies how long the isotopic abundance of 235U equal to 3.0 a/o
Thus, The time elapsed is
Answer:
Explanation:
When potassium chloride reacts with lead acetate in aqueous medium, it gives white precipitate of lead chloride and potassium acetate in aqueous medium as a product.
As shown in chemical reaction given below:
The density of the liquid is 0.98 g/mL
<h3>What is density? </h3>
The density of a substance is defined as the mass of the subtance per unit volume of the substance. Mathematically, it can be expressed as:
Density = mass / volume
With the above formula, we can obtain the density of the liquid.
<h3>How to determine the density </h3>
- Mass = 30.8 g
- Volume = 31.5 mL
- Density =?
Density = mass / volume
Density of liquid = 30.8 / 31.5
Density of liquid = 0.98 g/mL
Learn more about density:
brainly.com/question/952755
Mass = Density × Volume
= 30.0 mg / mL × 375 mL
= 11250 mg
= 11.25 g
∴ the total mass of insulin in the bottle is 11.25 g (11250 mg)
