A. When two chemicals mix their temperature rise: <span>Exothermic
b. </span>A solid burns brightly and releases heat, light and sound: <span>Exothermic
c. </span>When two chemicals are mixed their temperature drops: <span>Endothermic
d. </span>Two chemicals will only react if you heat them continually: <span>Endothermic
e. </span>Plants take in light energy for photosynthesis: <span>Endothermic
I hope this helps :)</span>
Using a more concentrated HCl solution and Crushing the CaCO₃ into a fine powder makes the reaction to occur at a faster rate.
<u>Explanation:</u>
CaCO₃(s) + 2HCl(aq) → CaCl₂(aq) + H₂O(aq) + CO₂(g)
When calcium carbonate reacts with hydrochloric acid, it gives out carbon-dioxide in the form of bubbles and there is a formation of calcium chloride in aqueous medium.
The rate of the reaction can be increased by
- Using a more concentrated HCl solution
- Crushing the CaCO₃ into a fine powder
When concentrated acid is used instead of dilute acid then the reaction will occur at a faster rate.
When CaCO₃ is crushed into a fine powder then the surface area will increases thereby increasing the rate of the reaction.
Answer:
Two electrons each!
Explanation:
The question pretty much requires us to find the oxidation number of Zinc in the compound.
Zn3P2
Following oxidation number rules;
O.N of Zn3P2 = 0
.Since phosphorus has valence of 5, it needs three more electrons to achieve its octet state. Hence;
Oxidation number of P = -3
Let oxidation number of Zn = x
We have;
3x + 2 (-3) = 0
3x + (-6) = 0
3x = 6
x = 6/3 = 2
This means each zn electrons lost 2 electrons.
The specific heat is the amount of heat per unit mass required to raise the temperature to 1 degree Celsius. (This is from google)
Sodium chloride has a high meltint point because of the strong electrostatic attraction between its positive and negative ions.
