Graduated cylinder
Stopwatch
Thermometer
The answer is 6.88.
Solution:
We can calculate for the percent composition of CaCl2 by mass by dividing the mass of the CaCl2 solute by the mass of the solution and then multiply by 100. The total mass of the resulting solution is the sum of the mass of CaCl2 solute and the mass of water solvent. Therefore, the percent composition of CaCl2 by mass is
% by mass = (mass of the solute / mass of the solution)*100
= mass of solute / (mass of the solute + mass of the solvent)*100
= (27.7 g CaCl2 / 27.7g + 375g) * 100
= 6.88
Answer:
An atom is a particle of matter that uniquely defines achemical element. An atom consists of a central nucleus that is usually surrounded by one or more electrons. Each electron is negatively charged. The nucleus is positively charged, and contains one or more relatively heavy particles known as protons and neutrons.
Explanation:
It is given that r = 0.283 nm. As 1 nm = 
.
Hence, 0.283 nm = 
- Formula for coulombic energy is as follows.
where, e = 
C
= 
= 
- As 1 eV =
So, 1 J = 
Hence, U = 
= 8.9 eV
- Also, 1 J =
= 
kJ/mol
Therefore, U = 
kJ/mol
= 
