Answer:
How many hydrogen MOLECULES are needed to produce 2 molecules of water (H2O)?
Explanation:
1. to calculate molar mass , you need average atomic mass of each element.
formula is simple
suppose we have Na2CO3
here it says
there are
2 atoms of Na
1 atom of C
3 atom of O
now
molar mass = (total atoms of Na × average atomic mass of Na) + ( total atom of C × average atomic mass of C )+ (total atom of O × average atomic mass of O)
i hope you can figure out it now.
in case of (NH4)2
this means you have 2 count of NH4
so total atoms of N = 2
total atoms of H = 4×2 = 8
so on you can now figure it out
2. balanced equation
here LHS and RHS shoild have same number of atoms of each element .
for example
H2 + Cl2 => 2HCl
here 2 atoms of H combined with 2 atoms of Cl , we know H and Cl combined and formed HCl now because total H atoms are 2 and Cl atoms are 2 in LHS then we should also have 2 atoms of each in right side
so thats why we have 2HCl in right side.
Try to figure out . let me know if need any help
Answer:
The mole fraction of NaOH in an aqueous solution that contain 22.9% NaOH by mass=0.882
Explanation:
We are given that
Aqueous solution that contains 22.9% NaOH by mass means
22.9 g NaOH in 100 g solution.
Mass of NaOH(WB)=22.9 g
Mass of water =100-22.9=77.1
Na=23
O=16
H=1.01
Molar mass of NaOH(MB)=23+16+1.01=40.01
Number of moles =
Using the formula
Number of moles of NaOH
Molar mass of water=16+2(1.01)=18.02g
Number of moles of water
Now, mole fraction of NaOH
=
=0.882
Hence, the mole fraction of NaOH in an aqueous solution that contain 22.9% NaOH by mass=0.882
Answer:
When substances do not mix thoroughly and evenly (like sand and gravel), the mixture is said to be heterogeneous. A heterogeneous mixture consists of visibly different substances. Another example of a mixture is salt dissolved in water.
Hope it helps!
Tell the teacher, do NOT clean it up yourself.
