Answer: Energy of reactants = 30, Energy of products = 10
Exothermic
Activation energy for forward reaction is 10.
Explanation:
Exothermic reactions are defined as the reactions in which energy of the product is lesser than the energy of the reactants. The total energy is released in the form of heat and 
for the reaction comes out to be negative.
Energy of reactants = 30
Energy of products = 10
Thus as energy of the product < energy of the reactant, the reaction is exothermic.
Activation energy 
is the extra energy that must be supplied to reactants in order to cross the energy barrier and thus convert to products.
for forward reaction is (40-30) = 10.
Answer:
74.81 grams of calcium carbonate are produced from 79.3 g of sodium carbonate.
Explanation:
The balanced reaction is:
Na₂CO₃ + Ca(NO₃)₂ ⟶ CaCO₃ + 2 NaNO₃
By reaction stoichiometry (that is, the relationship between the amount of reagents and products in a chemical reaction), the following amounts of each compound participate in the reaction:
- Na₂CO₃: 1 mole
- Ca(NO₃)₂: 1 mole
- CaCO₃: 1 mole
- NaNO₃: 2 mole
Being the molar mass of the compounds:
- Na₂CO₃: 106 g/mole
- Ca(NO₃)₂: 164 g/mole
- CaCO₃: 100 g/mole
- NaNO₃: 85 g/mole
then by stoichiometry the following quantities of mass participate in the reaction:
- Na₂CO₃: 1 mole* 106 g/mole= 106 g
- Ca(NO₃)₂: 1 mole* 164 g/mole= 164 g
- CaCO₃: 1 mole* 100 g/mole= 100 g
- NaNO₃: 2 mole* 85 g/mole= 170 g
You can apply the following rule of three: if by stoichiometry 106 grams of Na₂CO₃ produce 100 grams of CaCO₃, 79.3 grams of Na₂CO₃ produce how much mass of CaCO₃?
mass of CaCO₃= 74.81 grams
<u><em>74.81 grams of calcium carbonate are produced from 79.3 g of sodium carbonate.</em></u>
The air molecules in the compressions of the second wave are denser, so the sound is louder.
<h3>What is a sound wave?</h3>
Sound waves are longitudinal waves that travel through a medium like air or water.
In a closed room, Noah and Nina are sitting 15 m apart.
As Noah says the same sentence twice, Nina does not hear the sound the first time but she does hear the sentence the second time.
This happens as the air molecules in the compressions of the second wave are denser. As a result, the sound is louder.
The correct option is ''The air molecules in the compressions of the second wave are denser, so the sound is louder''.
Learn more about the sound wave here:
brainly.com/question/1554319
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If 30 grams of KCl is dissolved at 10°C, 14 g of KCl should be added to make a saturated solution at 60 °C.
<h3>What is a saturated solution?</h3>
A saturated solution is a solution in which there is so much solute that if there was any more, it would not dissolve. Its concentration is the same as the solubility at that temperature.
- Step 1. Calculate the mass of water.
At 10 °C, the solubility is 31.2 g KCl/100 g H₂O.
30 g KCl × 100 g H₂O/31.2 g KCl = 96 g H₂O
- Step 2. Calculate the mass of KCl required to prepare a saturated solution at 60 °C.
At 60 °C, the solubility is 45.8 g KCl/100 g H₂O.
96 g H₂O × 45.8 g KCl/100 g H₂O = 44 g KCl
- Step 3. Calculate the mass of KCl that must be added.
44 g - 30 g = 14 g
If 30 grams of KCl is dissolved at 10°C, 14 g of KCl should be added to make a saturated solution at 60 °C.
Learn more about saturated solutions here: brainly.com/question/24564260
Answer:
K > 1.
Explanation:
∵ The equilibrium constant K = [products]/[reactants].
Since, [products] > [reactants].
<em>∴ The equilibrium constant K > 1.</em>
