Given concentration of NaCl=15%
Means ,
In every 100g of Solution 15g of NaCl is present .
Now
So ,
<u>37.5g of NaCl present in 250g of solution.</u>
Answer:
63.58 g O
Explanation:
To calculate the mass of O atoms, the number of moles of O atoms are needed and can be calculated as follows:
n (no. of moles) = nA ÷ 6.02 × 10^23
n = 2.393 x 10^24 ÷ 6.02 × 10^23
n = 0.398 × 10^ (24-23)
n = 0.398 × 10^1
n = 3.98moles.
To calculate the mass of Oxygen, we use the following formula:
moles = mass/molar mass
Molar mass of O = 16.
3.98 = m/16
m = 3.98 × 16
m = 63.68grams of Oxygen.
First step is to balance the amount of atoms on each side
So for example if my equation that I have to balance is : Br2 -> Br-
First thing I would have to do would be :
Br2 -> 2Br-
Then I would have to balance the charges on both sides. So because there is a -2 charge on the right side I will have to add a -2 charge onto the right side as well. I would do this by :
Br2 + 2e- -> 2Br-
And now you can see the amount of atoms and the charges are balanced... So your overall reaction is now balanced too.
Answer:
Since rocks are denser than water, the water level will drop. The rocks in the boat will displace nearly the same amount of water as the rocks once thrown overboard. The difference would be the amount of water displaced by the boat itself and the person in it. Mass is mass whether in the water or the boat.
Explanation: