#6).
Every 1,000 mL makes 1 L
How many 1,000mL are there in 2,800 mL ?
That's division.
 (2,800 mL) / (1,000 mL) = 2.8 L

#7).
The 'perimeter' means the 'distance all the way around'.
You have to know that both sides of a rectangle are the same length,
and also the top and bottom are the same length.
So the perimeter of this rectangle is

 (2 yd) + (4.5 yd) + (2.yd) + (4.5 yd) = 13 yd .

Oops. The problem wants to know the perimeter in feet.
So you have to know that each yard is the same as 3 feet.
In order to find the number of feet in 13 yards, you have to
take 3 feet 13 times .

 (3 feet) times (13) = 39 feet .

#8).
For this one, you have to know that every 36 inches makes 1 yard.

How many 36 inches are there in 48 inches ?
That's division.
 (48 inches) / (36inches) = 1 and 1/2 yards .

#9).
For this problem, you have to know how to handle a mixed number,
and you also have to know that there are 16 ounces in 1 pound.

Add up the fruit:

 (3-1/2 pounds) + (4 pounds) + 2 pounds) = 9-1/2 pounds

Now, remember that each pound is the same as 16 ounces. So if you
want to find the number of ounces in 9-1/2 pounds, you have to take
16 ounces 9-1/2 times .

 (16 ounces) times (9-1/2) = 152 ounces.
___________________________________

#10).
This one is just adding up some numbers. But after you finish doing that, you have to know that 1,000 meters is called '1 kilometer' .

Add up the distances that Omar ran:

 (1,000 meters) + (1,625 meters) + (1,500 meters) = 4,125 meters

The problem wants to know how many kilometers this is, so you have to figure out how many '1,000 meters' fit into 4,125 meters.

That's division.

 (4,125 meters) / (1,000 meters) = 4.125 kilometers

4 0

4 years ago

For the galvanic (voltaic) cell Fe(s) + Mn2+(aq) → Fe2+(aq) + Mn(s) (E°= 0.77 V at 25°C), what is [Fe2+] if [Mn2+] = 0.040 M and

avanturin [10]

Answer:

0.01836 M

Explanation:

Again the reaction equation is;

Fe(s) + Mn2+(aq) → Fe2+(aq) + Mn(s)

E°cell= 0.77 V

Ecell= 0.78 V

[Mn2+] = 0.040 M

[Fe2+] = the unknown

n=2

From Nernst's equation;

Ecell= E°cell- 0.0592/n log Q

0.78= 0.77 - 0.0592/2 log [Fe2+] /[0.040]

0.78-0.77= - 0.0592/2 log [Fe2+] /[0.040]

0.01/ -0.0296= log [Fe2+] /[0.040]

-0.3378= log [Fe2+] /[0.040]

Antilog(-0.3378) = [Fe2+] /[0.040]

0.459= [Fe2+] /[0.040]

[Fe2+] = 0.459 × 0.040

[Fe2+] = 0.01836 M

7 0

3 years ago