Answer: A. Exothermic reaction
Explanation: Enthalpy change for a reaction is sum of enthalpy of formation of products minus sum of enthalpy of formation of reactants.
When the energy level of reactants is above as compared to the products, the reaction is exothermic and when its opposite then reaction is endothermic.
From given information, the potential energy diagram starts at 380 kJ means the energy level of reactants is 380 kJ. It ends at 100 kJ means the energy of products is 100 kJ.
Enthalpy of reaction = 100 kJ - 380 kJ
Enthalpy of reaction = -280 kJ
Negative sign of enthalpy change indicates an Exothermic reaction.
Answer:
The value of an integer x in the hydrate is 10.
Explanation:

Molarity of the solution = 0.0366 M
Volume of the solution = 5.00 L
Moles of hydrated sodium carbonate = n


Mass of hydrated sodium carbonate = n= 52.2 g
Molar mass of hydrated sodium carbonate = 106 g/mol+x18 g/mol



Solving for x, we get:
x = 9.95 ≈ 10
The value of an integer x in the hydrate is 10.
The number of atoms of each element :
C : 1 atom
H : 3 atoms
Br = 1 atom
<h3>Further explanation</h3>
Given
Bromomethane-CH₃Br
Required
The number of atoms
Solution
The empirical formula is the smallest comparison of atoms of compound forming elements.
A molecular formula is a formula that shows the number of atomic elements that make up a compound.
The number of atoms in a compound is generally indicated as a subscript after the atom
C : 1 atom
H : 3 atoms
Br = 1 atom
Total 5 atoms
The correct answer would be the last option. A double displacement type of reaction involves the switching of places the cations and anions accordingly. The given reaction is erroneous since in the product side the anions and cations are being paired which would not make sense. The correct reaction should be
4NaBr + Co(SO3)2 yields <span>CoBr4 + 2Na2SO3</span>
Boyle Law says “the pressure of fixed amount of ideal gas which is at constant temperature is
inversely proportional to its volume".<span>
P = 1/V
<span>Where, P is pressure of the ideal gas and V is volume of the ideal gas.</span>
<span>For two situations, this law can be added as;
P</span>₁V₁ = P₂V₂<span>
</span><span>14 lb/in² x V₁ = 70 lb/in² x 500 mL</span><span>
</span><span>V₁ =
2500 mL</span><span>
Hence, the needed volume of atmospheric air = 2500
mL
<span>Here, we made two </span>assumptions. They are,
1. The
atmospheric air acts as ideal gas.
2.
Temperature is a constant.
<span>We didn't convert the units to SI units since
converting volume and pressure are products of two numbers, they will cut off. </span></span></span>