4.) an element cannot be decomposed by a chemical change, it is a pure substance and no other materials compose it.
1.03!! Very easy you welcome:)
Is air a compound mixture or a element. compound
Answer:
Q = -33.6kcal .
Explanation:
Hello there!
In this case, according to the equation for the calculation of the total heat of reaction when a fixed mass of a fuel like ethane is burnt, we can write:

Whereas n stands for the moles and the other term for the enthalpy of combustion. Thus, for the required total heat of reaction, we first compute the moles of ethane in 3 g as shown below:

Next, we understand that -337.0kcal is the heat released by the combustion of 1 mole of ethane, therefore, to compute Q, we proceed as follows:

Best regards!
Answer:
The Kc of this reaction is 311.97
Explanation:
Step 1: Data given
Kp = 0.174
Temperature = 243 °C
Step 2: The balanced equation
N2(g) + 3H2(g) ⇌ 2NH3(g)
Step 3: Calculate Kc
Kp = Kc *(RT)^Δn
⇒ with Kp = 0.174
⇒ with Kc = TO BE DETERMINED
⇒ with R = the gas constant = 0.08206 Latm/Kmol
⇒ with T = the temperature = 243 °C = 516 K
⇒ with Δn = number of moles products - moles reactants 2 – (1 + 3) = -2
0.174 = Kc (0.08206*516)^-2
Kc = 311.97
The Kc of this reaction is 311.97