I found the rest of the exercise on the internet and these are the options.
"-Undifferentiated vertebrae throughout the body.
-One neck vertebra allowing up and down movement.
-Many neck vertebrae that allow for greater mobility.
<span>-Two neck vertebrae allowing up and down and sideways movement."
The correct answer would be the third. - "</span>Many neck vertebrae that allow for greater mobility." The <span>present-day organism with four limbs has a neck with several vertebrae that allow movements of rotation (mostly because of only two vertebrae at the top of the neck), and side way movements, as well as back and forth movements.</span>
Answer:
-1,103.39KJ/mol
Explanation:
We use the subtract the standard enthalphies of formation of the reactants from that of the products. It must be taken into consideration that the enthalpy of formation of elements and their molecules alone are not taken into consideration. Hence, what we would be considering are the standard enthalpies of formation of H2S, H2O and SO2.
In places where we have more than one mole, we multiply by the number of moles as seen in the balanced chemical equations.
The standard enthalpies of the molecules above are as follows:
H2S = -20.63KJ/mol
H2O = -285.8KJ/mol
SO2 = -296.84KJ/mol
O2 = 0KJ/mol
ΔrH⦵ = [2ΔfH⦵(H2O) + 2 ΔfH⦵(SO2)] − [ΔfH⦵(H2S) + 3
ΔfH⦵(O2)]
ΔrH⦵ =[(2 × -285.8) + (2 × -296.84)]
-[ 3 × -20.63)]
= (-571.6 - 593.68 + 61.89) = -1,103.39KJ/mol
The answer is <span>Plastics, Medicine, Clothing, Paper. </span>Coal is used in the making of Plastics, Medicine, Clothing, Paper. Some important users of coal include alumina refineries, paper manufacturers, and the chemical and pharmaceutical industries. Thousands of different products have coal or coal by-products as components: soap, aspirins, solvents, dyes, plastics and fibres, such as rayon and nylon.
Answer:
147.2g
Explanation:
The full solution can be found in the image attached. Graham's law was applied to the problem. The rate of diffusion of a gas is inversely proportional to its molar mass or vapour density. Molar mass= 2vapour density
