PLEASE HELP ASAP I NEED TO HAND IN TOMORROW A chemist prepares an aqueous solution of magnesium chloride using a redox reaction between magnesium and dilute hydrochloric acid. The equation for the reaction is shown below:
Mg(s) + 2HCl(aq) → MgCl2(aq) + H2(g)

The chemist reacts 8.1 x 10+g of magnesium with a solution of 0.500 mol dm-3 hydrochloric acid.

a) Calculate the amount, in moles, of magnesium in 8.1 x 10-'g of pure magnesium. Give your answer to an appropriate number of significant figures. 2 marks

b) Calculate the amount, in moles of hydrochloric acid required to react with 8.1 x 10-'g of magnesium. Give your answer to an appropriate number of significant figures. 1 mark​

you need to give more information

answer: c. the experiment shows that the red substance experienced a chemical change.

explanation: chemical change is the change in which chemical composition of the substance changes. physical change is the change in which there is no change in chemical composition.

chemical changes are accompanied by following changes:

a) precipitate formation

b) energy is released or absorbed

c) formation of bubbles

d) change in color

as it is given that the red color has disappeared and there is production of gas, it means the red substance has undergone a chemical change.

e

answer:

the answer is 6 valence electrons.

explanation:

valence is the # of electrons on the outer most shell of an atom.

oxygen has 6.

although, the valency of oxygen is 2, because it only needs to make 2 covalent bonds, or gain 2 electrons, to achieve the stable octet configuration of a noble gas.

that's it!

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