<h3>
Answer:</h3>
52 mm
<h3>
Explanation:</h3>
We are given;
Required to convert it to cm
We are going to use the appropriate conversion factor;
- The units used to measure length include;
Kilometer(km)
10
Hectometer (Hm)
10
Decameter (dkm)
10
Meter(m)
10
Decimeter (dm)
10
Centimeter (cm)
10
Millimeter (mm)
Therefore; the appropriate conversion factor is 10mm/cm
Thus;
5.2 cm will be equivalent to;
= 5.2 cm × 10 mm/cm
= 52 mm
Therefore, the length of magnesium ribbon is 52 mm
One mole of copper equals 6.02 × 10^23 atoms. The answer is letter C. This follows the
Avogaro’s law wherein 1 mole of a substance is equal to 6.02 x 10^23 atoms,
formula units or molecules. This is applicable to all substances.
228 grams
start with mass of Cr multiply by molar mass of Cr mole to mole ratio between Cr and Cr2O3 times molar mass of Cr2O3
Answer:
D. A compound can be separated into two or more elements through a chemical reaction.
Explanation:
By method of elimination, we are going t obtain the correct option.
A. A compound is made up of a single atom.
This is wrong because, a compound can contain more than one atom. An example is H2O
B. A compound is made up of many atoms that are all the same type.
This is wrong because a compound can contain atoms of different elements. An example is H2O. It contains atoms of hydrogen and oxygen.
C. A compound can be separated into two or more elements through physical processes.
This is wrong. H2O being a compound cannot be separated by ordinary physical means.
D. A compound can be separated into two or more elements through a chemical reaction.
This is the correct option.
Answer:
872.28 kJ/mol
Explanation:
The heat released is:
ΔH = C*ΔT
where ΔH is the heat of combustion, C is the heat capacity of the bomb plus water, and ΔT is the rise of temperature. Replacing with data:
ΔH = 9.47*5.72 = 54.1684kJ
A quantity of 1.922 g of methanol in moles are:
moles = mass / molar mass
moles = 1.992/32.04 = 0.0621 mol
Then the molar heat of combustion of methanol is:
ΔH/moles = 54.1684/0.0621 = 872.28 kJ/mol
