Answer: 4.1 g of barium precipitated.
Explanation:
According to avogadro's law, 1 mole of every substance occupies 22.4 L at STP and contains avogadro's number 
of particles.
To calculate the moles, we use the equation:
Given : moles of barium = 0.030
Molar mass of barium = 137 g/mol
x= 4.1 g
Thus there are 4.1 g of barium that precipitated.
The oxidation state of Hydrogen in reactant side is 0 and that in product side is +1. Hence the reaction is oxidation.
Answer: II. The catalyst provides a new pathway in the reaction mechanism.
III. The catalyst speeds up the reaction.
Explanation:
Activation energy is the extra energy that must be supplied to reactants in order to cross the energy barrier and thus convert to products.
A catalyst is a substance which increases the rate of a reaction by taking the reaction through a different path which involves lower activation energy and thus more molecules can cross the energy barrier and more molecules convert to products.
The catalyst itself does not take part in the chemical reaction and gets regenerated as such at the end of the reaction without getting consumed.
The answer is b damaged tissue can not be repaired
After it passes an area there will be colder<span>, drier </span>air<span> and clear skies. This </span>occurs when a fast-moving warm air mass overtakes a slowly moving cold air mass<span>.</span>
