ANSWERS:
Group 2 metal carbonates, nitrates and hydroxides decompose to heat to give the corresponding metal oxide and release CO2, NO2 and O2, and H2O respectively. The thermal stability increases down the group as theionic character of the compounds increases down the group.
Answer: definite proportions.
Explanation:
1) The definite proportions law states that compounds will always have the same kind of atoms (elements) in the same mass proportion (ratios).
2) For example, a molecule of water will alwys have the same mass ratio of hydrogen atoms to oxygen atoms. That is what permits to obtain the chemical formula of the water molecule as H₂O.
The mass of the two hydrogen atoms will be in a fixed ratio respect to the mass of the oxygen atoms.
Then, if you have one reactant in less proportion than the other, respect to the ratio stated by the chemical formula of water, the former will react completely (it is the limiting reactant) with the corresponding (proportional) mass of the later. Then there will be an excess of the later reactant which will not react (will remain unchanged).
The reactants can only react in the proportion defined by the chemical formulas of the final products.
In rubidium oxide - Rb₂O , the ions are Rb⁺ and O²⁻
Rb is a group one element with one valence electron. To become stable it loses its outer electron to gain a complete outer shell.
Electronic configuration of Rb is - 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 5s¹
Once it loses its valence electron the configuration is;
- 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶
The noble gas with this configuration is Krypton - Kr
Oxygen electron configuration is 1s² 2s² 2p⁴
Once it gains 2 electrons the configuration is - 1s² 2s² 3p⁶
The noble gas with this configuration is Neon - Ne
Answer: weigh is m = n × M = 2.87 mol × 58.44 g/mol
Explanation: mass = amount of substance × molar mass
M((NaCl) = 22.99 +35.45
Answer:
Heating the system
Explanation:
According to the principle of Le Chatelier, for a system at equilibrium, a specific disturbance would make the equilibrium shift toward the direction which minimizes such a disturbance.
Since we wish to shift the equilibrium to the left, this means we wish to increase the concentration of products, as an excess in their concentration would make the products react and produce more reactants in order to lower the excess concentration of products.
Since heat is also a product, an increase in heat would shift the equilibrium toward the left, as this would consume the excess of heat by producing the reactants.
