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
2 Na₂CO₃ + 2 CuSO₄ + H₂O → CuCO₃.Cu(OH)₂ + 2 Na₂SO₄ + CO₂
Malachite molar mass = 221.1 g / mol
So 2 moles CuSO₄ produce 1 mole of malachite
so 1.5 mole CuSO₄ produce (0.75) mole malachite
Mass of malachite = 0.75 mole * 221.1 g/ mol = 165.83 g
Answer:
The concentration is [-1 + sqrt(1+0.11t)]/0.1542 M
Explanation:
Let the concentration of CH3CHO after selected reaction times be y
Rate = Ky^2 = change in concentration of CH3CHO/time
K = 0.0771 M^-1 s^-1
Change in concentration of CH3CHO = 0.358 - y
0.0771y^2 = 0.358-y/t
0.0771ty^2 = 0.358 - y
0.0771ty^2 + y - 0.358 = 0
The value of y must be positive and is obtained in terms of t using the quadratic formula
y = [-1 + sqrt(1^2 -4(0.0771t)(-0.358)]/2(0.0771) = [-1 + sqrt(1+0.11t)]/0.1542 M
The mass of NaCl sample has been 24.3 g. Thus, option A is correct.
The heat of fusion has been the amount of heat required to convert 1 mole of substance into solid to liquid state.
The heat required has been given as:
<h3>Computation for the mass of NaCl</h3>
The given solution has heat of fusion, 
The heat required to melt the sample has been, 
Substituting the values for the mass of NaCl
The mass of NaCl sample has been 24.3 g. Thus, option A is correct.
Learn more about heat of fusion, here:
brainly.com/question/87248
2 Na + 2 H2O → 2 NaOH + H2 (balanced equation)
The answer would be 2, since 2 in the coefficient of both Na and NaOH
