The first one and last one I think
Answer:
all pure substance are molecules
Answer:
B)
Explanation:
UV increases earths temp making global warming
Answer:
0.0102moles CaCl₂.2H₂O
0.0102moles CaCl₂
Explanation:
To convert moles to grams or vice versa of a compound, it is necessary to find molar mass of this substance.
For the CaCl₂.2H₂O:
This is the calcium chloride dihydrate (Because there are 2 molecules of water). That means you have 1 atom of Ca, 2 atoms of Cl, 4 atoms of H and 2 atoms of C. <em>Molar mass is the algebraic sum of the atomic weights that compose the molecule. </em>
Molar mass:
Ca: 1ₓ40.08g/mol = 40.08g/mol
Cl: 2ₓ35.45g/mol = 70.90g/mol
H: 4ₓ1.01g/mol: 4.04g/mol
O: 2ₓ16g/mol: 32g/mol.
40.08 + 70.90 + 4.04 + 32 = <em>147.02g/mol</em>
By using the molar mass of the susbtance, 1.50g are:
1.50g ₓ (1mol / 147.02g) =
<h3>0.0102moles CaCl₂.2H₂O</h3>
In the 1.50g of CaCl₂.2H₂O you have 0.0102 moles. As you can see, 1 mole of the dihydrate substance contains 1 mole of CaCl₂. Thus, you have:
<h3>0.0102moles CaCl₂</h3><h3 />