Answer:
C
Explanation:
Think of 'exo' as exit and 'thermic' as relating to thermal energy/ heat. Thus, an exothermic release thermal energy as the reaction proceeds.
In an exothermic reaction, the total energy of the products is lesser than that of the reactants and ΔH (change in energy) is less than zero.
When heat is absorbed as the reaction proceeds, the chemical reaction is an endothermic reaction.
Answer:
6.7970 g
Explanation:
Considering the Henderson- Hasselbalch equation for the calculation of the pOH of the basic buffer solution as:
pOH = pK + log[acid] / [base]
Where K is the dissociation constant of the base.
Base dissociation constant of the ammonia = 1.8×10⁻⁵
pK = - log (Kb) = - log (1.8×10⁻⁵) = 4.75
Given concentration of base = [base] = 0.273 M
pH = 10.150
pOH = 14 - pH = 14 - 10.150 = 3.85
So,
3.85 = 4.75 + log[acid]/0.273
[Acid] = 0.0347 M
Given that Volume = 2 L
So, Moles = Molarity × Volume
Moles = 0.0347 × 2 = 0.0694 moles
Molar mass of ammonium bromide = 97.94 g/mol
Mass = Moles × Molar mass = (0.00775 × 97.94) g = 6.7970 g
Water and carbon dioxide are waste products released as a direct result of materials
HCl is the formula for hydrocloric acid
Answer:
Explanation:
Given parameters:
Mass of water = 40g
Initial temperature = 33°C
Final temperature = 23°C
Specific heat capacity of water = 4.2J/g°C
Unknown:
Quantity of heat = ?
Solution:
To solve this problem, we use the expression below;
H = m c Δt
H is the quantity of heat
m is the mass
c is the specific heat capacity
Δt is the change in temperature
H = 40 x 4.2 x (23 - 33) = -1680J
The water will have to lose 1680J of heat to bring it to that final temperature.