Answer:
8
Explanation:
You are going to divide the 24 moles of H by the moles of H used in Ammonia. In this case 3
24/3=8
Answer:
The time taken for the cross to become invisible decreases.
Explanation:
We know that one of the factors affecting the rate of reaction is the concentration of reactants. From the collision theory, we know that the higher the concentration of reactants, the greater the possibility of effective collision between reactants leading ultimately to an increase in the rate of reaction. Increase in the rate of reaction implies that the reaction takes a shorter time to reach completion.
In the case of the reaction shown in the question, the point when the reaction is completed is observed by the time take for the cross mark to become invisible. If we look at the given data closely, we will notice that the volume of acid was held constant, the volume of thiosulphate was increased gradually while the volume of water was decreased accordingly. This implies that the concentration of the reactants was increased. Decreasing the volume of water increases reactant concentration.
As explained above, increase in reactant concentration increases the rate of reaction. Hence, the rate of reaction of the acid and thiosulphate increases as reactant concentration increases and the cross mark becomes invisible faster. This implies that in the last column for time taken for the cross to become invisible, the values of time decreases steadily as concentration of reactants increases.
Answer:
Chemical symbol
This is used to identify an element without having to write the full name and as such is a designation for the element. It is used in chemical reactions and is usually either one or two letters. Some symbols are, Iron - Fe, Hydrogen - H and Oxygen - O.
Valency
This refers to the capacity of an element to combine with another to form a compound. It is measured by the number of electrons that an atom of an element gains, looses or shares when a chemical reaction involving it takes place.
Answer: 2NOBr(g) ⇌ 2NO(g) + Br2(g)
Explanation: For volume changes in equillibrium, the following are to be taken into consideration:
- Volume changes have no effect on equillibrium system that contains solid or aqueous solutions.
- An increase in volume of an equilibrium system will shift to favor the direction that produces more moles of gas.
- A decrease in volume of an equilibrium system will shift to favor the direction that produces less moles of gas.
- Volume changes will have no effect on the equillibrium system if there is an equal number of moles on both sides of the reaction.
2NOBr(g) ⇌ 2NO(g) + Br2(g) is the equillibrium system because there are more moles of products,therefore an increase in the volume of the reaction will shift to the right and produce more moles of products. Also both reactants and products exist in the gaseous state and does not have equal number of moles.
The answer is D, because "Animals without a backbone are invertebrates."
