Stoichometry part2
B,Mole-ratio method
It is the ratio between the number of moles if any substance is given reaction.
#In this method the given mass is converted into mole
-the number of mole for the required substance
Example what mass of water is required when 100g of calcium oxide react with water to produce calcium hydroxide? (atomic mass Ca-40,0-16, H-1)
Cao + H2O---> Ca (OH)2
MOLe of Cao-given mass/molar mass
n Cao=100g/56g/mol
n CaO=1.79mol
(1.79mol) CaO (1mol) + (x) H2O (1mol) --> Ca(OH)2
1.79mol/1mol=x/4mol
X=1.9 mol1 mol)/1mol
X=1,7mol
2. VOLUME VOLUME RELATIONSHIP
#At standard temperature pressure (STP)
1mol=22.4L=1atm =25°c
The relation b/n volume of gas and its number of molecule explained by AVOGADRO'S LAW
Avogadro's law-state that" Under the same condition of the temperature and pressure equal volume of all gas contain the same number of molecules and vice versa
V~n
Example-How many liters of ammonia are produced at STP if 501 of hydrogen reacted with enough nitroge
(22.4L) 3H2(50L) + N2-> (224)2NH3(x)
501/67.21-X/44.8)
X=50-44.8/67.2
X=33,33 L of ammonia
3, MASS -VOLUME RELATIONSHIP
-In this problem, either the mass og one substance is given the volume of the other required or the volume of one substance is given and the mass of the other one required
Example-How many gram of calcium carbonate are decomposed to produced 11.21 of CO2 at STP
(X) CaCo3 (100g ---> CaO (11.2L) CO2 (22.4L)
X/100g=11.2L/22.4L
X=11.2*100/22.4
X-50g of CaCO3
B,Mole-ratio method
It is the ratio between the number of moles if any substance is given reaction.
#In this method the given mass is converted into mole
-the number of mole for the required substance
Example what mass of water is required when 100g of calcium oxide react with water to produce calcium hydroxide? (atomic mass Ca-40,0-16, H-1)
Cao + H2O---> Ca (OH)2
MOLe of Cao-given mass/molar mass
n Cao=100g/56g/mol
n CaO=1.79mol
(1.79mol) CaO (1mol) + (x) H2O (1mol) --> Ca(OH)2
1.79mol/1mol=x/4mol
X=1.9 mol1 mol)/1mol
X=1,7mol
2. VOLUME VOLUME RELATIONSHIP
#At standard temperature pressure (STP)
1mol=22.4L=1atm =25°c
The relation b/n volume of gas and its number of molecule explained by AVOGADRO'S LAW
Avogadro's law-state that" Under the same condition of the temperature and pressure equal volume of all gas contain the same number of molecules and vice versa
V~n
Example-How many liters of ammonia are produced at STP if 501 of hydrogen reacted with enough nitroge
(22.4L) 3H2(50L) + N2-> (224)2NH3(x)
501/67.21-X/44.8)
X=50-44.8/67.2
X=33,33 L of ammonia
3, MASS -VOLUME RELATIONSHIP
-In this problem, either the mass og one substance is given the volume of the other required or the volume of one substance is given and the mass of the other one required
Example-How many gram of calcium carbonate are decomposed to produced 11.21 of CO2 at STP
(X) CaCo3 (100g ---> CaO (11.2L) CO2 (22.4L)
X/100g=11.2L/22.4L
X=11.2*100/22.4
X-50g of CaCO3
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Geography Model Examination Geography Model Examination for Grade 12for Grade 12
1. What are the influence factors for prevalence of high temperature and salient difference of annual
temperature range in tropical hot zone?
A. Due to it is location from the sea C. Because of it receive solar radiation at right angel
B. Due to its position toward ocean current D. Because of the impact of trade winds
2. If internal forces act towards each other from the opposite directions, the consequence it brings on the
surface of the earth is
A. Mountain range B. Rift valley C. Deep valley D. Plain surface
3. One of the following features of land form was not found in rift valley?
A. Volcano’s B. Hot springs C. Lakes D. High mountain range
4. What happens to the surface of the earth if sun radiation is reaching the ground totally?
A. Life impossible to survive C. Slant difference from the Present situation
B. In curtains degree temperature differ D. Temperature decrease
5. If the altitude of given mountain is 8848 meters above the sea level and temperature at the sea level is 00C,
what will be expected temperature at the top of the mountain?
A. 500C B. 56.70C C. 550C D. 600C
6. Al l of the following activities are the outcome of internal force, except?
A. Folding B. Volcanism C. Bending D. Erosion
7. Barchans are:
A. Wind eroded stone C. Crescent shaped sand dune
B. Wind eroded deposition D. Desert sand storm
8. In the process of land formation the way in which sofomar cave creation is?
A. Deposition B. Carbonation C. weathering D. Erosion
9. All of the following location is laid in Afro_ Alpine areas, except?
A. Senate plateau B. Choke Mountain C. Semen mountain D. Hararghe plateau
10. From the land forms list below one is not associated with wind erosion activities?
A. Sand dune B. Loess deposited C. Barchans D. Lagoon
11. Within vertical structure of atmospheric layer areas that have constant temperature is?
A. Troposphere B. Mesosphere C. Stratosphere D. Thermosphere
12. Which one is wrong combination of elements of weather & climate with instruments of their
measurements?
A. Temperature & thermometer C. Rainfall & rain gage
B. Air pressure & isobar D. Wind & wind vane
13. In the process of atmospheric mass movements depend up on its temperature variation the cold
push the warms one, this process is known as?
A. Convection B. Radiation C. Conduction D. Evaporation
1. What are the influence factors for prevalence of high temperature and salient difference of annual
temperature range in tropical hot zone?
A. Due to it is location from the sea C. Because of it receive solar radiation at right angel
B. Due to its position toward ocean current D. Because of the impact of trade winds
2. If internal forces act towards each other from the opposite directions, the consequence it brings on the
surface of the earth is
A. Mountain range B. Rift valley C. Deep valley D. Plain surface
3. One of the following features of land form was not found in rift valley?
A. Volcano’s B. Hot springs C. Lakes D. High mountain range
4. What happens to the surface of the earth if sun radiation is reaching the ground totally?
A. Life impossible to survive C. Slant difference from the Present situation
B. In curtains degree temperature differ D. Temperature decrease
5. If the altitude of given mountain is 8848 meters above the sea level and temperature at the sea level is 00C,
what will be expected temperature at the top of the mountain?
A. 500C B. 56.70C C. 550C D. 600C
6. Al l of the following activities are the outcome of internal force, except?
A. Folding B. Volcanism C. Bending D. Erosion
7. Barchans are:
A. Wind eroded stone C. Crescent shaped sand dune
B. Wind eroded deposition D. Desert sand storm
8. In the process of land formation the way in which sofomar cave creation is?
A. Deposition B. Carbonation C. weathering D. Erosion
9. All of the following location is laid in Afro_ Alpine areas, except?
A. Senate plateau B. Choke Mountain C. Semen mountain D. Hararghe plateau
10. From the land forms list below one is not associated with wind erosion activities?
A. Sand dune B. Loess deposited C. Barchans D. Lagoon
11. Within vertical structure of atmospheric layer areas that have constant temperature is?
A. Troposphere B. Mesosphere C. Stratosphere D. Thermosphere
12. Which one is wrong combination of elements of weather & climate with instruments of their
measurements?
A. Temperature & thermometer C. Rainfall & rain gage
B. Air pressure & isobar D. Wind & wind vane
13. In the process of atmospheric mass movements depend up on its temperature variation the cold
push the warms one, this process is known as?
A. Convection B. Radiation C. Conduction D. Evaporation
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