Answer:
Explanation:
Figure 6. An instant cold pack consists of a bag containing solid ammonium nitrate and a second bag of water. When the bag of water is broken, the pack becomes cold because the dissolution of ammonium nitrate is an endothermic process that removes thermal energy from the water.
Answer: molecular formula = C12H16O8
Explanation:
NB Mm CO2= 44g/mol
Mm H2O= 18g/mol
Moles of CO2 = 36.86/44=0.84mol
0.84mole of CO2 has 0.84 mol of C
Moles of H2O = 10.06/18= 0.56mol
1mol of H20 contains 1mol of O and 2 mol H,
Hence there are 0.56mol O and (0.56×2)mol H
Hence the compound contains
C= 0.84 mol H= 1.12mol O=0.56mol
Divide through by smallest number
C= 0.83/0.56= 1.5mol
H= 1.12/0.55= 2mol
O= 0.56/0.56= 1mol
Multiply all by 2 to have whole number of moles = 3:4:2
Hence empirical formula= C3H4O2
(C3H4O2)n = 288.38
[(12×3) + 4+(16×2)]n= 288.38
72n=288.38
n= 4
:. Molecular formula=(C3H4O2)4= C12H16O8
Number of moles = 0.0688 moles of NaoH
volume = 0.250 L
Molarity = moles of solute / volume ( L )
M = 0.0688 / 0.250
M = 0.28 M
Answer B
You need the Avogadro's number. I can't remember exactly the calculation.
