Explanation:
A physical change is one that alters the physical properties of matter (particularly the form and state).
A chemical change is one in which new kind of matter is formed. It is always accompanied by energy changes (evolution or absorption of energy in form of heat or light or both).
Now, the salient differences between physical and chemical changes;
- Physical changes are easily reversible whereas chemical changes are not easily reversible.
- Physical changes lead to the production of no new kinds of matter whereas chemical changes leads to the production of new kinds of matter.
- Physical changes involves no change in mass whereas chemical changes involves change in mass.
- Physical changes require little energy whereas considerable amount of energy is needed for chemical changes.
The only logical answer is A
Answer:
30moles of SiO₂
Explanation:
Given parameters:
Number of moles of O₂ = 30moles
Unknown:
Number of moles of SiO₂ = ?
Solution:
To solve this problem, we need to write the reaction expression:
Si + O₂ → SiO₂
The reaction is balanced;
1 mole of O₂ will produce 1 mole of SiO₂
30mole of O₂ will produce 30moles of SiO₂
B and e
first we need to balance the NH3 hence first we do E and multiplying the coefficient by 2. that will leave us with N2+H2–>2NH3.
N2 and H2 is balanced and now all that is left to do is the balance H2 by 3 as there is 6H on RHS hence we need 6H on LHS
