Explanation:
1. The three factors are;
- Increasing the surface area of the reactants
- Using a catalyst
- Increasing temperature
2. Raising the temperature of a reaction mixture is the same as increasing the kinetic energy of the reacting molecules.
3. This reaction is an exothermic reaction. In exothermic reaction, the temperature of the system (mixture) decreases while that of the surroundings increases.
4. Reactions that releases energy to the surroundings are exothermic reactions.
5. All the options is an example of exothermic process because heat is being removed from the system except;
B. Evaporation of water - This is because it must absorb heat from the surroundings making it endothermic.
Phenolphthalein turns pink when mixed with bases; since Mg(OH)2 is the only base, it is the answer.
Answer:
potassium (K) and bromine (Br)
Explanation:
- Periodic table is a table of elements in terms of rows and columns in terms of their chemical and physical properties.
- Elements in the same group or columns have similar physical and chemical properties. For example, elements in the same group have the same number of valence electrons or valency.
- Elements in the same period or rows have similar number of energy levels. For example, potassium and bromine belong to the same period in the periodic table and thus have the same number of energy levels.
Potassium chlorate decomposes to form potassium chloride and oxygen.
Balancefd equation is as follows;
2KClO₃ --> 2KCl + 3O₂
stoichiometry of KClO₃ to O₂ is 2:3
At STP, 1 mol of any gas occupies a volume of 22.4 L.
Number of moles in 22.4 L is - 1 mol
Therefore in 11.2 L - 1/22.4 x 11.2 = 0.5 mol
When 3 mol of O₂ are formed - 2 mol of KClO₃ react
therefore when 0.5 mol of O₂ are formed - 2/3 x 0.5 = 0.33 mol of KClO₃ reacted
Therefore 0.33 mol of KClO₃ are required
the mass of KClO₃ required - 0.33 mol x 122.5 g/mol = 40.43 g