You must remember that oxidation number of hydrogen in acids is always +1, oxidation number of oxygen in oxides & acids is always -2... metals has always oxidation number on plus!
group NO3 comes from HNO3...and oxidation number of whole acid group is always on minus and equal to the amount of hydrogen atoms in this acid... so oxidation number of NO3 = -1
we have 2 NO3 groups so 2*(-1) = -2 and that is the reason why oxidation number of Fe in this formula must be +2... because sum of all elements always gives 0!
Now we could count of oxidation number for nitrogen... we write HNO3 and start counting from right to left:
3*(-2) from oxygens + 1 from hydrogen = -5
so nitrogen must have +5 oxidation number... because sum all in formula must be 0.
The minerals in hard water react with soap and affect its cleaning capacity. It's still possible to use hard water when washing by using more soap. The additional soap will no longer be affected by the minerals in the water, so they can clean just as effectively, but you'll be wasting more soap this way.
Answer
i’m in 7th grade but for this years science fair i did, “ how does temperature affect the elasticity of rubber bands”
Guide a growing plant through a maze.
8th Grade Science Plant Maze KiwiCo
Prove that plants really do seek out the light by setting up a simple or complex maze. This is a simple 8th grade science project with really cool results.
Blow out a candle with a balloon.
Blowing up a balloon with baking soda and vinegar is the classic acids and bases experiment. Take it a step further by experimenting with the carbon dioxide it produces. (Don’t be afraid of fire in the science
Stand on a pile of paper cups.
Combine physics and engineering and challenge 8th grade science students to create a paper cup structure that can support their weight. This is a cool project for aspiring architects.
hope this helps and have a wonderful day :)
Answer:
94.61 %
Explanation:
percent yield = (actual yield / theoretical yield) X 100%
The balanced equation for the reaction is:
H2 (g ) + Cl2(g) => 2 HCl (l)
So, the theoretical yield =
7.25g of chlorine X (2mol of Cl / 35.453 g of Cl) X (2mol Cl / 2mol of HCl) X 37.469g of Hcl / 2mol of Hcl = 0.409 x 18.735 = 7.663g of Hcl
Using this theoretical yield and the provided value for actual yield, the percent yield = (actual yield / theoretical yield) X 100%
= (7.25 g / 7.663g) X 100
= 94.61 %
