Answer:
119 kCal per serving.
Explanation:
The heat energy necessary to elevates water's temperature from 23.4°C to 37.9°C can be calculated by the equation below:
Q = mcΔT
Q: heat energy
m: mass in g
c: specific heat capacity in cal/g°C
ΔT = temperature variation in °C
m is the mass of water, considering the density of water to be 1g/mL, 100 mL of water weights 100g. Therefore:
Q = 100 g x 1.00 cal/g°C x (37.9 - 23.4)°C
Q = 1450 cal
1450 cal ____ 0.341 g peanuts
x ____ 28 g peanuts
x = 119061.58 cal
This means that the cal from fat per serving of peanuts is at least 119 kCal.
The question is incomplete. The complete question is:
Calcium Carbide (CaC₂) is an unusual substance that contains a carbon anion (C₂²⁻). The reaction with water involves several steps that occur in rapid succession. CaC2 is a salt (notice that its name is similar to sodium chloride). When a salt dissolves in water, ions leave the crystal lattice and enter the aqueous (aq) solution. Write the relevant balanced chemical equation for the dissolution of CaC₂, in water.
Answer:
CaC₂(s) + 2H₂O(l) → Ca(OH)₂(aq) + C₂H₂(aq)
Explanation:
When a salt dissolves in water, it dissociates in its ions. In the Calcium Carbide, the cation is Ca⁺² and the anion is C₂²⁻, so the reaction is:
CaC₂(s) + 2H₂O(l) → Ca(OH)₂(aq) + C₂H₂(aq)
The base Ca(OH)₂ is soluble, so it will dissociate at Ca⁺ and OH⁻, but the C₂H₂ is stable and doesn't dissociate in the solution.
The correct answer should be B.
The correct answer would be B.
