1. Pour water to the 2.0 mL mark in the graduated cylinder. If you look at the graduated cylinder from the side, you will see the water forms a curve. Make sure the bottom of the curve is at the 2.0 mL
mark
2. Use the gram scale to measure the mass of the graduated cylinder and 2.0 mL of water. Record the
mass in the table. Calculate the mass of 2.0 mL of water by subtracting the mass of the graduated
cylinder
3. Repeat this process to find and record the mass of 4.0 mL of water and then 6.0 mL of water.
4. Density is mass in grams divided by volume in cubic centimeters (cm²). 1 mL is equal to 1 cm.

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

observation, evidence