Answer:
Mass = 6.538 g
Explanation:
Given data:
Mass of zinc hydroxide produced = 9.65 g
Mass of zinc required = ?
Solution:
Chemical equation:
Zn + 2MnO₂ + H₂O → Zn(OH)₂ + Mn₂O₃
Number of moles of zinc hydroxide:
Number of moles = mass/molar mass
Number of moles = 9.65 g/ 99.42 g/mol
Number of moles = 0.1 mol
now we will compare the moles of zinc and zinc hydroxide,
Zn(OH)₂ : Zn
1 : 1
0.1 : 0.1
Mass of zinc required:
Mass = number of moles × molar mass
Mass = 0.1 mol × 65.38 g/mol
Mass = 6.538 g
1) (Hvap)(moles of water)=236.9783574kJ
(40.67)(105/18.02)
2) (change in temperature)(mass)(Cliquid)=43.9345172kJ
(100)(105/18.02)(75.4)/1000
3) (Hfus)(moles of water)=35.01942286kJ
(6.01)(105/18.02)
4) (change in temperature)(mass)(Csolid)=3.181465039kJ
(15)(105/18.02)(36.4)/1000
Total released=319.1137625kJ
5. B air is a mixture of many elements, but is not a chemically fused.
6. B Beef stew, composition varies throughout.
7. A. They can be chemically separated into their component elements, but they are all homogenous, and as such, have constant composition, which differs from the components properties, as the components must undergo a chemical change to become compounds.
The molarity of a solution is the number of moles of a substance divided by the volume in liters prepared.
, where n is number of moles and V is the volume in liters.
In order to calculate the mass of solute we need to convert the volume and molarity to moles

Now that we have moles we use the relative formula mass of NaCO₃, We have 1 Na atom, 1 C atom and 3 O atoms, thus


<span>Answer:
A 0.04403 g sample of gas occupies 10.0-mL at 289.0 K and 1.10 atm. Upon further analysis, the compound is found to be 25.305% C and 74.695% Cl. What is the molecular formula of the compound?
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Seems like I did a problem very similar to this--this must be the "B" test. But the halogen was different.
25.305% C/12 = 2.108
74.695% Cl/35.5 = 2.104
So the empirical formula would be CH. However, there are many compounds which fit this bill, so we have to use the gas data. (And I made, in the previous problem, the simplifying assumption that 289C and 1.10 atm would offset each other, so I'll do that, too.)
0.044 grams/10 ml = x/22.4 liters
0.044g/0.010 liters = x/22.4 liters
22.4 liters/0.010 liters = 2240 (ratio)
2240 x .044 = 98.56 (actual atomic weight)
CCl = 35.5+12 or 47.5, so two of those is 95 grams/mole.
This is sufficiient to distinguish C2CL2, (dichloroacetylene)
from C6CL6 (hexachlorobenzene) which would
mass 3 times as much.</span>