Answer:
-56.1kJ/mol
Explanation:
The reaction between HCl and NaOH is:
NaOH + HCl → NaCl + H₂O + ΔH
<em>Where ΔH is heat change in the reaction.</em>
<em />
As the temperature of the solution increases, the heat is released and ΔH < 0
The heat released in the reaction is obtained using coffe-cup calorimeter equation:
Q = C×m×ΔT
<em>Where Q is heat</em>
<em>C is specific heat of the solution (4.184J/g°C)</em>
<em>m is mass of solution: Assuming density = 1g/mL, 100mL of solution = 100g</em>
<em>And ΔT is change in temperature (13.4°C)</em>
<em />
Replacing:
Q = C×m×ΔT
Q = -4.184J/g°C×100g×13.4
Q = -5606.6J
Now, in the reaction you have:
<em>Moles HCl:</em>
0.050L * (2.2mol/L) = 0.11 moles
<em>Moles NaOH:</em>
0.050L * (2.0mol/L) = 0.1 moles
That means the moles of reaction are 0.1 moles, and heat change in the chemical reaction is:
5606.6J / 0.1 mol = 56066J =
<h3>-56.1kJ/mol</h3>
<em />
Answer:
Two
Explanation:
The law of conservation of mass states that in an isolated system the mass present is neither destroyed nor created by chemical changes or physical changes.
This tells us that the mass of reactants must be equal to the product mass.
If 1 atom of Zn react with one atoms of sulfur, the product will be 1 molecule of zinc sulfide according to the equation below
Zn(s) + S(s) ⇒ ZnS(s)
therefore two atoms each f zinc and sulfur will product two molecules of Zn sulfide
1 molecule of NH3 has 3 atoms of H.
6.90*10²⁴ molecules NH3 have 3*6.90*10²⁴ =20.7*10²⁴ atoms H=2.07*10²⁵ atoms H
1 molecule H2O of has 2 atoms of H.
2.60*10²⁵ molecules of H2O have 2*2.60*10²⁵ =5.20 *10²⁵ atoms of H
2.07*10²⁵ + 5.20 *10²⁵ =7.27*10²⁵ atoms of H altogether.
The concentration of a and b will decrease while c will increase provided all other physical quantities are kept constant in the reaction
