<span>Avogadro's number
represents the number of units in one mole of any substance. This has the value
of 6.022 x 10^23 units / mole. This number can be used to convert the number of
atoms or molecules into number of moles. We calculate as follows:
</span>5.31×10^21 platinum atoms ( 1 mol / 6.022 x 10^23 atoms ) ( 78 grams / 1 mol ) = 0.6878 grams platinum
Answer:
45 joules to calories= 10 (10.755258) calories
Answer:
atomic structure - The nucleus is at the center of an atom, where most of the charge and mass are concentrated
protons - a stable subatomic particle occurring in all atomic nuclei, with a positive electric charge equal in magnitude to that of an electron, but of opposite sign.
neutrons - a subatomic particle of about the same mass as a proton but without an electric charge, present in all atomic nuclei except those of ordinary hydrogen.
electrons - a stable subatomic particle with a charge of negative electricity, found in all atoms and acting as the primary carrier of electricity in solids.
atom vs. ion - an atom is the basic unit of a chemical element, and an ion is an atom or molecule with a net electric charge due to the loss or gain of one or more electrons. See also cation, anion.
Mass number - total number of protons, and neutrons in an atom.
Explanation:
i hope this is what you were looking for.
<span>Consider the following reaction:
2CH3OH(g)→2CH4(g)+O2(g)ΔH=+252.8kJ
Calculate the amount of heat transferred when 27.0g of CH3OH(g) is decomposed by this reaction at constant pressure.
27.0 g </span>CH3OH(g) (1 mol/ 32.05g) = 0.84 mol CH3OH(g)
ΔH =+252.8kJ = Q = 0.84 mol (252.8kJ) = 213 kJ
