Paul is describing a mineral to douglas over the phone. he explains that it has the same texture throughout but the color on the inside is different from the color on the outside. douglas tells paul that -
a) he is correct. paul has a mineral.
b) he is incorrect. a mineral has many textures.
c) he is correct. a mineral has one texture but more than one color.
d) he is incorrect. a mineral has just one color, inside and outside.

just did the assignment and the answer was #1 +2 n

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