Answer:
Q = -33.6kcal .
Explanation:
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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:

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<span>Various gases and liquids have different densities and combustion points.</span>
Seas are smaller than oceans. Oceans are where land and water meet, and are usually bigger.
Answer:
pH = 12.80
[H3O+] = 1.58 * 10^-13 M
[OH-] = 0.063 M
Explanation:
Step 1: Data given
pOH = 1.20
Temperature = 25.0 °C
Step 2: Calulate pH
pH + pOH = 14
pH = 14 - pOH
pH = 14 - 1.20 = 12.80
Step 3: Calculate hydronium ion concentration
pH = -log[H+] = -log[H3O+]
12.80 = -log[H3O+]
10^-12.80 = [H3O+] = 1.58 * 10^-13 M
Step 4: Calculate the hydroxide ion concentration
pOH = 1.20 = -log [OH-]
10^-1.20 = [OH-] = 0.063M
Step 5: Control [H3O+] and [OH-]
[H3O+]*[OH-] = 1* 10^-14
1.58 *10^-13 * 0.063 = 1* 10^-14
Answer: 11 electrons
Explanation: The atomic number of sodium is 11. This tells us that sodium has 11 protons and because it is neutral it has 11 electrons.