Answer:
178.98 sq. feet
Explanation:
The path and the garden has been shown in the figure below. The green area is the garden and the area in brown is the path.
It has been given that,
Radius of garden = 8 feet
So, the area of garden = 3.14 × 8 × 8 = 200.96 sq. feet
The total radius of the land including garden and path = 8 + 3 = 11 feet
So, the total are of land including garden and path = 3.14 × 11 × 11 = 379.94 sq. feet
So, the area of path = Total area of the land - area of garden
Area of path = 379.94 - 200.96 = 178.98 sq. feet
The answer is true, catalysts increase rates by lowering the activation energy of a reaction. Catalysts lower the reaction energy and so the reaction occurs faster. Enzymes perform the role of biological catalysts. Most metabolic pathways of the body are controlled by enzymes. Enzymes by classification are proteins. <span />
Answer:
1249.88 mol.
Explanation:
∵ no. of moles of Fe = mass of Fe/atomic weight of Fe.
<em>∴ no. of moles of Fe </em>= (6.98 x 10⁴ g)/(55.845 g/mol) = <em>1249.88 mol.</em>
<span>Answer:
Nothing is balanced in your final equation: not H, not O, not Cr, not I and your charges aren't either.
Start with your 2 half reactions:
I- --> IO3-
Cr2O72- --> 2 Cr3+
Balance O by adding H2O:
I- + 3 H2O --> IO3-
Cr2O72- --> 2 Cr3+ + 7H2O
Balance H by adding H+:
I- + 3 H2O --> IO3- + 6 H+
Cr2O72- + 14 H+ --> 2 Cr3+ + 7H2O
Balance charge by adding e-:
I- + 3 H2O --> IO3- + 6 H+ + 6 e-
Cr2O72- + 14 H+ + 6 e- --> 2 Cr3+ + 7H2O
Since the numbers of electrons in your two half reactions are the same, just add them and simplify to give:
Cr2O72- + I- + 8 H+ --> IO3- + 2 Cr3+ + 4 H2O</span>
Which of the following measurements is expressed to three significant figures?
C. 5.60 km
Hope this helps!
