So in a chemical change, the product would loses its properties, would form new products and would not be easily reversed.
In a physical change, the products WILL NOT lose any of their properties, WILL NOT form any new products and WILL be easily reversed.
Talking about Water turning to ice I would say it’s all about physical change and not chemical change.
But I would suggest you to either make a research about it or ask your teacher :))
Answer:
d . al of these
Explanation:
all of that are used when you in spaceship
Answer: 72.4 kJ/mol
Explanation:
The balanced chemical reaction is,
The expression for enthalpy change is,
![\Delta H=\sum [n\times \Delta H_f(product)]-\sum [n\times \Delta H_f(reactant)]](https://tex.z-dn.net/?f=%5CDelta%20H%3D%5Csum%20%5Bn%5Ctimes%20%5CDelta%20H_f%28product%29%5D-%5Csum%20%5Bn%5Ctimes%20%5CDelta%20H_f%28reactant%29%5D)
![\Delta H=[(n_{CO_2}\times \Delta H_{CO_2})+(n_{H_2O}\times \Delta H_{H_2O})]-[(n_{O_2}\times \Delta H_{O_2})+(n_{C_3H_8}\times \Delta H_{C_3H_8})]](https://tex.z-dn.net/?f=%5CDelta%20H%3D%5B%28n_%7BCO_2%7D%5Ctimes%20%5CDelta%20H_%7BCO_2%7D%29%2B%28n_%7BH_2O%7D%5Ctimes%20%5CDelta%20H_%7BH_2O%7D%29%5D-%5B%28n_%7BO_2%7D%5Ctimes%20%5CDelta%20H_%7BO_2%7D%29%2B%28n_%7BC_3H_8%7D%5Ctimes%20%5CDelta%20H_%7BC_3H_8%7D%29%5D)
where,
n = number of moles
(as heat of formation of substances in their standard state is zero
Now put all the given values in this expression, we get
![-2220.1=[(3\times -393.5)+(4\times -241.8)]-[(5\times 0)+(1\times \Delta H_{C_3H_8})]](https://tex.z-dn.net/?f=-2220.1%3D%5B%283%5Ctimes%20-393.5%29%2B%284%5Ctimes%20-241.8%29%5D-%5B%285%5Ctimes%200%29%2B%281%5Ctimes%20%5CDelta%20H_%7BC_3H_8%7D%29%5D)
Therefore, the heat of formation of propane is 72.4 kJ/mol
Answer: 4 x 10 ∧-2 moles of nitrogen.
Explanation:
The chemical formular for quinine is ; C20 H24 N2 O2
As can be seen from the chemical formular;
1 mole of quinine contains 2 moles of Nitrogen
Thus; 2.0 x 10 ∧-2 moles of quinine would contain
2.0 x 10 ∧-2 x 2 = 4 x 10 ∧-2 moles of nitrogen.
Therefore 4 x 10 ∧-2 moles of nitrogen are in 2.0×10−2mole of quinine
