Answer:
15.75g
Explanation:
Rearrange the formula: density = mass/volume, so that mass is the subject: mass = density × volume
Now substitute (plug in) the known values into the formula:
mass = 10.5 × 1.5 ⇒ mass = 15.75g
The mass of the silver necklace is 15.75g
Hope this helps!
The given question is incomplete. The complete question is:
The combustion of propane (C3H8) in the presence of excess oxygen yields
and
When only 2.5 mol of
are consumed in order to complete the reaction, ________ mol of
are produced.
Answer: Thus when 2.5 mol of
are consumed in their reaction, 1.5 mol of
are produced
Explanation:
The balanced chemical equation is:

According to stoichiometry :
5 moles of
produce = 3 moles of 
Thus 2.5 moles of
will produce =
moles of 
Thus when 2.5 mol of
are consumed in their reaction, 1.5 mol of
are produced
Answer:
CO + 2H2 = CH3OH
Explanation:
1. Label Each Compound With a Variable
aCO + bH2 = cCH3OH
2. Create a System of Equations, One Per Element
C: 1a + 0b = 1c
O: 1a + 0b = 1c
H: 0a + 2b = 4c
3. Solve For All Variables (using substitution, gauss elimination, or a calculator)
a = 1
b = 2
c = 1
4. Substitute Coefficients and Verify Result
CO + 2H2 = CH3OH
L R
C: 1 1 ✔️
O: 1 1 ✔️
H: 4 4 ✔️