Please help! Geologists determine the hardness of a mineral using the Mohs scale of hardness. Why is it important for geologists to be able to do these tests in the field?

To help determine what type of rock it is

Explanation:

Geologists can use information such as color, hardness, grain size, texture and other aspects of the rock to figure out the classification of a rock. for example, a light blue rock with no visible grain that is translucent and has a hardness of 9 is most likely going to be a saphire. hope this helps

as given the equation is

2al + 6 hcl > 2 alcl3 + 3 h2(g)

as per equation two moles of aluminum reacts with six moles of hcl to give two moles of alcl3 and three moles of hydrogen gas

given: three moles of al are present and 7 moles of hcl

for three moles of aluminum nine moles of hcl will be required

however as 7 moles of hcl are present so the limiting reagent is hcl

hcl is going to decide the number of moles of product formed

when six moles of hcl are present = 3 moles of h2 are formed

when one mole of hcl is present == 3/6 mole sof h2 will be formed

when 7 moles of hcl are present = 3 x 7/ 6 moles of h2 will be formed = 3.5 moles of h2