Procedures that are likely a chemical change are:
- Bubbles were produced when iron was placed in acid.
- Two liquids were combined, and a solid appeared
- A white substance turned blue when water was added.
Answer:
C. air pollution absorbs carbon dioxide
Explanation:
Carbon dioxide's role in the greenhouse effect is a major contributor to air pollution. Radiation and heat emanating from the earth's surface need to be released out into the atmosphere. But because carbon dioxide levels are so high, there is an ozone effect on the ground level.
Answer:
Approximately 
.
Explanation:
Note that both figures in the question come with four significant figures. Therefore, the answer should also be rounded to four significant figures. Intermediate results should have more significant figures than that.
<h3>Formula mass of strontium hydroxide</h3>
Look up the relative atomic mass of 
, 
, and 
on a modern periodic table. Keep at least four significant figures in each of these atomic mass data.
Calculate the formula mass of 
:
.
<h3>Number of moles of strontium hydroxide in the solution</h3>
means that each mole of formula units have a mass of 
.
The question states that there are 
of in this solution.
How many moles of formula units would that be?
.
<h3>Molarity of this strontium hydroxide solution</h3>
There are 
of formula units in this 
solution. Convert the unit of volume to liter:
.
The molarity of a solution measures its molar concentration. For this solution:
.
(Rounded to four significant figures.)
Answer:
2.645
Explanation:
Rate of diffusion formula:
Sqrt(mass2/mass1)
>>sqrt(14/2)
(Note:Hydrogen must exist in dwiatomic, [H2])
.
.
.