1 mole of platinum has a mass of 195 g therefore 1 atom will have a mass of 195 g /(6.02 ×10^23) = 3.239 × 10^-22 g
Density is given by dividing mass by volume, thus to get volume, mass is divided by density.
The volume = (3.239 × 10^-22)/21.4
= 1.514 × 10^-23 cm³
But volume of a sphere is given by 4/3πr³
Therefore, r³ = 3.6129 × 10^-24
r = ∛(3.6129 × 10^-24)
= 1.534 × 10^ -8 cm
Therefore, the radius of the platinum atom is 1.534 × 10^-8 cm
Answer:An increase in temperature commonly will increase the rate of reaction. An growth in temperature will improve the common kinetic electricity of the reactant molecules.
Explanation:
<u>Given:</u>
Enthalpy change (ΔH) for SO3 decomposition = +790 kJ
Moles of SO3 = 2.1 moles
<u>To determine:</u>
Energy required when 2.1 moles of SO3 reacts
<u>Explanation:</u>
The decomposition reaction is -
2SO3(g) → 2S(s) + 3O2 (g)
Energy required when 2 moles of SO3 reacts is 790 kJ
Thus, for 2.1 moles of SO3 the energy requirement would be
= 2.1 moles SO3 * 790 kJ/2 moles SO3 = 829.5 kJ
Ans: 830 kJ are required when 2.1 moles of SO3 reacts.
Answer:
Explanation:
The half-life of carbon (5730 y) is the time it takes for half the carbon to decay.
After one half-life, half (50 %) of the original amount will remain.
After a second half-life, half of that amount (25 %) will remain, and so on.
We can construct a table.
<u>No of half-lives</u> <u>Fraction remaining</u>
1
2
3
The general formula is

where <em>n</em> = the number of half-lives.
Thus,
of the original carbon remains after 17 190 y.