The atomic structure of the atom contains 9 positively charged particles (protons) and 10 neutrally charged particles (neutrons) in the center of the atom in a clump called the nucleus. Those 9 negatively charged particles (electrons) are moving around outside of the nucleus.
There are 10 neutral charges, because the mass of 19 comes from the number of neutral charges plus the number of positive charges.
To calculate the number of neutral charges, subtract the positive charges from the mass (19 - 9), and you get the number of neutral charges (10).
Answer:
0.84 mol
Explanation:
Given data:
Moles of ZnCl₂ produced = ?
Mass of Zn = 55.0 g
Solution:
Chemical equation:
2HCl + Zn → ZnCl₂ + H₂
Number of moles of Zn:
Number of moles = mass / molar mass
Number of moles = 55.0 g/ 65.38 g/mol
Number of moles = 0.84 mol
Now we will compare the moles of Zn with ZnCl₂ from balance chemical equation.
Zn : ZnCl₂
1 : 1
0.84 : 0.84
So from 55 g of Zn 0.84 moles of zinc chloride will be produced.
Answer:
Explanation:
Stoichiometry is based on the <u>conservation of mass</u>.
<u>Given:</u>
Mass of Ba = 1.50 g
Mass of H2O = 100.0 g
Initial temp T1 = 22 C
Final Temp T2 = 33.1 C
specific heat c = 4.18 J/g c
<u>To determine:</u>
The reaction enthalpy
<u>Explanation:</u>
The heat released during the reaction is:
q = - mc(T2-T1) = - (100+1.5) g *4.18 J/g C * (33.1-22) C = -4709.4 J
# moles of Ba = Mass of Ba/Atomic mass of Ba = 1.5 g/137 g.mol-1 = 0.0109 moles
ΔH = q/mole = - 4709.4 J/0.0109 moles = - 432 kJ/mol
Ans : The enthalpy change for the reaction is -432 kJ/mol
