Chemical changes are irreversible.
A chemical change that could happen at school would be when you have a chemistry experiment and you mix an acid and a base such as mixing hydrochloric acid with sodium hydroxide.
A chemical change that could happen at home would be baking a cake. You can't take the ingredients used in baking a cake back apart because they have changed their chemical composition.
A chemical change that happens in nature could be a forest fire. The burning of wood would be the chemical change in this case.
<span>Conservation of energy implies that energy can be neither created nor destroyed, although it can be changed from one form into another.</span>
Answer:
he amount of heat gained by the water is 1.59 kJ
Explanation:
Relation between heat energy, specific heat and temperature change is as follows
Q = mCΔT
where, Q or q = heat energy
m = mass
C = specific heat =4.186J/g°C
ΔT = (28°C - 25°C) = 3°C
Now, putting the given values into the above formula as follows.
Q = mCΔT
= 127 × 4.186 × 3
= 1594.86 J or 1.59 kJ
Therefore, we can conclude that the amount of heat gained by the water is 1.59 kJ
Answer:
Identify each equation as a composition reaction, a decomposition reaction, or neither.
Fe2O3 + 3 SO3 → Fe2(SO4)3
NaCl + AgNO3 → AgCl + NaNO3
(NH4)2Cr2O7 → Cr2O3 + 4 H2O + N2
Solution
In this equation, two substances combine to make a single substance. This is a composition reaction.
Two different substances react to make two new substances. This does not fit the definition of either a composition reaction or a decomposition reaction, so it is neither. In fact, you may recognize this as a double-replacement reaction.
A single substance reacts to make multiple substances. This is a decomposition reaction.
Test Yourself
Identify the equation as a composition reaction, a decomposition reaction, or neither.
C3H8 → C3H4 + 2 H2
Explanation:
I hope I help :)))
Answer:
3.6 moles of Na
Explanation:
Reaction is this one:
2Na + Cl₂ → 2NaCl
Ratio is 2:2, so 3.6 moles of NaCl could come from 3.6 moles of Na,
If we have to convert the mass to moles
3.6 mol . 23 g/mol = 82.8 g
