First write out the eqn, and balance it.
next, take 12.8g/mr of aluminium
this will give u the mols of aluminium
next, take the ratio of HCL and Al, compare and find the mols of HCL.
take the mols of HCL/mr of HCL to give u mass
doneee
<span>Actually, the heat of reaction hrxn s calculated by taking
the sum of the heats of formation of the products minus the sum of the heats of
formation of the reactants. However, at heat of formations of pure elements at
atmospheric conditions is zero, therefore the hf of N2 is not important since
it is zero anyway.</span>
In order to solve the total pressure that is exerted by the gases, we need to use the Dalton's Law of Partial pressures. These are the calculations that you need to find out the total amount of pressure exerted to the gases:
3.00atm (N2) + 1.80atm (O2) + 0.29atm (Ar) + 0.18atm (He) + 0.10atm (H),
add up all of that, and the answer would turn out to be: 5.37atm.
Answer:
Explanation:
Given parameters:
pH = 3.50
Unknown:
concentration of [H₃0⁺] = ?
concentration of [OH⁻] = ?
Solution:
In order to find the unknown, we use some simple expressions which best explains the pH scale and the equilibrium systems of aqueous solutions.
pH = -log₁₀[H₃O⁺]
[H₃O⁺] = inverse log₁₀ (-pH) =
= 
[H₃O⁺] = 3.2 x 10⁻⁴moldm⁻³
For the [OH⁻]:
we use : pOH = -log₁₀ [OH⁻]
Recall: pOH + pH = 14
pOH = 14 - pH = 14 - 3.5 = 10.5
Now we plug the value of pOH into pOH = -log₁₀ [OH⁻]
[OH⁻] = 
[OH⁻] =
= 3.2 x 10⁻¹¹moldm⁻³
The solution is acidic as the concentration of H₃0⁺ is more than that of the OH⁻ ions.