Answer:
The heat of reaction when hydrogen and oxygen combine to form water is :
<u>C. 571.6 kJ</u>
Explanation:
Enthalpy Change = The enthalpy change for the formation of 1 mole of the substance from their standard state is called the enthalpy of formation.
This is intensive quantity as it is fixed for 1 mole .
Intensive properties = Those properties which are independent on the amount of the substance are intensive properties.
The value of these quantities does not get halve if you divide the substance into two equal parts. example , density, refractive index.
However , the enthalpy of reaction is extensive. Because on increasing the amount the value of the enthalpy also get doubles
Hence for this reaction :
Its value is -285.8 kJ for 1 mole
And here two moles are present . so the value of molar enthalpy is:
-285.8 x 2 = -571.6 kJ
The rate of chemical reactions generally happen <em>faster</em> when the temperature is raised.
This happens because the reactant's molecules move faster when the temperature is raised. The molecules start to bounce around more, increasing the chance for the reaction to happen, or to increase the speed at which the reaction occurs. Hope this helped.
The correct option is C. The amount of MgCl2. we know this because <span>no matter how much you increase KOH, if you dont increase Mgcl2, the amount of Mg(OH)2 remains the same. Hope this works for you</span>
In one mole of talc, we observe that there are:
3 moles of Mg
4 moles of Si
2 moles of H
12 moles of O
The molar ratio of O to Mg is then:
12 moles of O : 3 moles of Mg = 4 : 1
Therefore, if 6.1 moles of Mg are present, the moles of O are:
4 * 6.1 = 24.4 moles of O