Answer:
2.03 moles of Gold
Explanation:
Gold is one of the most precious metal metal used in many applications and mainly as a jewellery. In terms of purity it is categorized in Karats. 24 Karat is considered the purest Gold (i.e. 100 % Gold) while other Karats (14, 18, 22 e.t.c) are alloys with other metals and gyms.
Data Given:
Mass of Gold = 400 g
A.Mass of Gold = 196.97 g.mol⁻¹
Calculate Moles of Gold as,
Moles = Mass ÷ M.Mass
Putting values,
Moles = 400 g ÷ 196.97 g.mol⁻¹
Moles = 2.03 moles of Gold
Answer: Th enthalpy of combustion for the given reaction is 594.244 kJ/mol
Explanation: Enthalpy of combustion is defined as the decomposition of a substance in the presence of oxygen gas.
W are given a chemical reaction:



To calculate the enthalpy change, we use the formula:

This is the amount of energy released when 0.1326 grams of sample was burned.
So, energy released when 1 gram of sample was burned is = 
Energy 1 mole of magnesium is being combusted, so to calculate the energy released when 1 mole of magnesium ( that is 24 g/mol of magnesium) is being combusted will be:

Answer:
Rate = k . [B]² . [C]
Explanation:
The dependence of the reaction rate on the concentration of the reactants is given by the reaction order of each one, as shown in the rate equation.
![Rate=k.[A]^{x} .[B]^{y} .[C]^{z}](https://tex.z-dn.net/?f=Rate%3Dk.%5BA%5D%5E%7Bx%7D%20.%5BB%5D%5E%7By%7D%20.%5BC%5D%5E%7Bz%7D)
where,
k is the rate constant
x, y, z are the reaction orders.
- <em>The rate of reaction is not affected by changing the concentration of species A.</em> This means that the reaction order for A is x = 0 since when its concentration changes, the rate stays the same.
- <em>Leaving all other factors identical, doubling the concentration of species B increases the rate by a factor of 4.</em> This means that the reaction order for B is y = 2, so when the concentration is doubled, the new rate is 2² = 4 times the initial rate.
- The rate of the reaction is linearly dependent on the concentration of C. This means that the reaction order for C is z = 1, that is, a linear dependence.
All in all, the rate equation is:
Rate = k . [B]² . [C]
Carbon dioxide can’t exist in three states; Gas, Liquid & Solid. At normal temperatures and pressures, CO2 is colorless with a slightly pungent odor at high concentrations. If compressed and cooled to proper temperature the gas liquifies. Solid CO2, (dry ice) sublimates back to the natural gaseous state.