Answer:
We need 6.0 moles of aluminium
Explanation:
Step 1: Data given
Number of moles of H2 = 9.0 moles
Step 2: The balanced equation
2 Al + 6 HCl → 2 AlCl3 + 3H2
Step 3: Calculate moles Al
For 2 moles Aluminium, we need 6 moles HCl to produce 2 moles AlCl3 and 3 moles H2
For 9.0 moles of H2 we need 2/3 * 9.0 = 6.0 moles of aluminium
We need 6.0 moles of aluminium
Answer:
An unconformity is a widespread surface separating rocks above and below, which represents a gap in the rock record. Unconformities occur when either erosion wears away rocks, or rock deposits never form. Therefore, a time gap exists between when the rocks below the unconformity formed and when those above it formed.
Explanation:
Iodine and Calcium is the correct answer
The mass defect for the isotope thorium-234 if given mass is 234.04360 amu is 1.85864 amu.
<h3>How do we calculate atomic mass?</h3>
Atomic mass (A) of any atom will be calculated as:
A = mass of protons + mass of neutrons
In the Thorium-234:
Number of protons = 90
Number of neutrons = 144
Mass of one proton = 1.00728 amu
Mass of one neutron = 1.00866 amu
Mass of thorium-234 = 90(1.00728) + 144(1.00866)
Mass of thorium-234 = 90.6552 + 145.24704 = 235.90224 amu
Given mass of thorium-234 = 234.04360 amu
Mass defect = 235.90224 - 234.04360 = 1.85864 amu
Hence required value is 1.85864 amu.
To know more about Atomic mass (A), visit the below link:
brainly.com/question/801533
