Answer: 38L
Explanation:
Initial volume of helium V1 = 35 L
Initial temperature T1 = 20°C
Convert temperature in Celsius to Kelvin
(20°C + 273 = 293K)
New volume V2 = ?
New Temperature T2 = 45°C
(45°C + 273 = 318K)
Since, volume and temperature are involved while pressure is constant, apply the formula for Charles' Law:
(V1/T1) = (V2/T2)
35L/293K = V2/318K
0.119 = V2/318K
To get V2, cross multiply
V2 = 0.119 x 318
V2 = 38L
Thus, the new volume of the balloon is 38 liters
Answer:
Percentage by mass of calcium carbonate in the sample is 93.58%.
Explanation:
Assumptions:
- calcium carbonate was dissolved completely and the amount of carbon dioxide released was proportional to the amount of calcium carbonate.
- the sample did not contain any other compound that released or reacted with carbon dioxide.






given the equation of the reaction:

from assumption:
amount carbon dioxide = amount of calcium carbonate

reacting mass ( m ) = Molar Mass ( M ) * Amount ( n )

m = 0.04938397
* 100
= 4.93839 
percentage by mass of CaC
=
.
I already answered this question in Spanish language. Now I answer in English.
Answer: the chemical changes.
Explanation:
We understand by composition of a substance to the proportion (ratio or percentage) of each element (type of atoms) that makes up the same, as well as the way in which these elements are linked (chemical bonds).
A chemical change is a process, also called a chemical reaction, in which one or more substances are converted into different substances.
The resulting substances are different because their composition is different, since some chemical bonds have been broken and others have been formed, giving rise to a new structure. The chemical formula of each compound product of the chemical change will present a different combination of atoms, in ratio or structure.