true gas molicules bounce off one another much faster liquid just slides
Answer:
-800 kJ/mol
Explanation:
To solve the problem, we have to express the enthalpy of combustion (ΔHc) in kJ per mole (kJ/mol).
First, we have to calculate the moles of methane (CH₄) there are in 2.50 g of substance. For this, we divide the mass into the molecular weight Mw) of CH₄:
Mw(CH₄) = 12 g/mol C + (1 g/mol H x 4) = 16 g/mol
moles CH₄ = mass CH₄/Mw(CH₄)= 2.50 g/(16 g/mol) = 0.15625 mol CH₄
Now, we divide the heat released into the moles of CH₄ to obtain the enthalpy per mole of CH₄:
ΔHc = heat/mol CH₄ = 125 kJ/(0.15625 mol) = 800 kJ/mol
Therefore, the enthalpy of combustion of methane is -800 kJ/mol (the minus sign indicated that the heat is released).
Answer:
There are two sets of groups in the periodic table. The first set are Group A elements and are also known as representative elements. The second set are Group B elements and are also known as transition metals. Representative elements are the most abundant elements on earth.
8.50 moles is equal to 5.1187×10²⁴ atoms of Ca.
<u>Explanation:</u>
We have to multiply the moles of Ca by the Avogadro's number:
= 6.022×10²³
So the number of atoms:
= 8.5 moles × 6.022×10²³atoms / mol
= 5.1187×10²⁴ atoms
Hence the 8.50 moles is equal to 5.1187×10²⁴ atoms of Ca.
Answer:
A flower is self-pollinated if pollen is transferred to it from any flower of the same plant and cross-pollinated if the pollen comes from a flower on a different plant.
Explanation:
This is because each flower is capable of fertilizing itself by autogamy. Autogamy means that the male part of a flower sends pollen to the female part of the same flower.
