Ca Cl2(aq) Ca2+(aq) + 2Cl-(aq)
No. of moles of CaCl2250/1000×1=0.25m
? No. of moles of Cl- ion = 0.25 x 2
= 0.5m
? No of chloride ions 0.5 x 6.0 x 1023
= 3.0 x 1023 ions
Lywascomputers answered the question on August 19, 2018 at 18:25
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On complete combustion of a hydrocarbon gas X, 1.32g of carbon (IV) oxide and 0.54g of water. Calculate the empirical formula of X
(Solved)
On complete combustion of a hydrocarbon gas X, 1.32g of carbon (IV) oxide and 0.54g of water. Calculate the empirical formula of X (C = 12.0, H = 1, O = 16.0)
Date posted:
August 19, 2018
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Answers (1)
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Study the following information and answer the question that follows
(Solved)
Study the following information and answer the question that follows.
Heat of hydration of x2+ = -1480 kJ/mol
Heat of hydration y- = -364 kJ/mol
Lattice energy of XY2 = +2112 kJ/mol
Determine the heat evolved when 31.8g of XY2(s) is dissolved in water to give an infinitely dilute solution. (RAM of Z = 88, Y = 35.5)
Date posted:
August 19, 2018
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Answers (1)
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(Solved)
Distinguish between a strong acid and a concentrated acid
Date posted:
August 19, 2018
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Answers (1)
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Give two reasons why during preparation of salt, it is advisable to heat the solution to concentration allowing it to cool in order to crystallize
(Solved)
Give two reasons why during preparation of salt, it is advisable to heat the solution to concentration allowing it to cool in order to crystallize instead of heating to dryness.
Date posted:
August 19, 2018
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Answers (1)
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In an experiment it was found that 40.0cm3 of 0.2M sodium hydroxide solution just neutralized 0.2g of a dibasic acid Q..
(Solved)
In an experiment it was found that 40.0cm3 of 0.2M sodium hydroxide solution just neutralized 0.2g of a dibasic acid Q. Calculate the relative molecular mass of acid Q.
Date posted:
August 19, 2018
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Answers (1)
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The nitrates of the following metals were heated strongly and observation made accordingly. The nitrate of metal P produced the metallic oxide, Nitrogen (IV) oxide and oxygen gas
(Solved)
The nitrates of the following metals were heated strongly and observation made accordingly. The nitrate of metal P produced the metallic oxide, Nitrogen (IV) oxide and oxygen gas; and that of metal Q produced the metallic nitrite and oxygen gas. The nitrate of R produced metal R, Nitrogen (IV) oxide and oxygen gas. Arrange the metals in order of reactivity beginning with the most reactive
Date posted:
August 19, 2018
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Answers (1)
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A student was asked to prepare Lead (II) chloride salt using the following ingredients; Nitric (V) acid, lead (II) oxide and hydrochloric..
(Solved)
A student was asked to prepare Lead (II) chloride salt using the following ingredients; Nitric (V) acid, lead (II) oxide and hydrochloric acid. Using ionic equations only explain how the salt can be prepared.
Date posted:
August 19, 2018
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Answers (1)
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Paper chromatography is a method of separating colours or dyes. What two properties should the components of a mixture have...
(Solved)
Paper chromatography is a method of separating colours or dyes.
What two properties should the components of a mixture have that would make the separation possible
Date posted:
August 19, 2018
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Answers (1)
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Dilute nitric acid is added to excess green solid. Effervescence occurs and a blue solution is formed. When excess ammonia solution is added to a sample..
(Solved)
Dilute nitric acid is added to excess green solid. Effervescence occurs and a blue solution is formed. When excess ammonia solution is added to a sample of the solution a deep blue solution is formed.
Identify the anion and cation in the green solid.
Date posted:
August 18, 2018
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Answers (1)
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Nitrogen (IV) Oxide is passed through a combustion tube before Copper is heated. Give a reason
(Solved)
Nitrogen (IV) Oxide is passed through a combustion tube before Copper is heated. Give a reason.
Date posted:
August 18, 2018
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Answers (1)
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Name the products formed when ammonia (I) Is burnt in air with excess oxygen...
(Solved)
Name the products formed when ammonia:
(I) Is burnt in air with excess oxygen
(II) Oxidized in presence of platinum catalyst
(III) Decompose when heated
Date posted:
August 17, 2018
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Answers (1)
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(Solved)
State two distinctive features of dynamic equilibrium
Date posted:
August 17, 2018
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Answers (1)
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(Solved)
Give three factors that accelerate rusting
Date posted:
August 16, 2018
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Answers (1)
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10.26 g of aluminium sulphate were dissolved in 200cm3 water. Calculate the molar concentration of the sulphate ions in the solution
(Solved)
10.26 g of aluminium sulphate were dissolved in 200cm3 water. Calculate the molar concentration of the sulphate ions in the solution (Relative formula mass of aluminium sulphate = 342).
Date posted:
August 15, 2018
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Answers (1)
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An oxide of silicon was found to contain 47% by mass silicon. What is the empirical formula of the oxide? (Si=28,O=16)
(Solved)
An oxide of silicon was found to contain 47% by mass silicon. What is the empirical formula of the oxide? (Si=28,O=16)
Date posted:
August 13, 2018
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Answers (1)
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Determine the number of moles in 13.5 g of aluminium (Al =27)
(Solved)
Determine the number of moles in 13.5 g of aluminium (Al =27)
Date posted:
August 13, 2018
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Answers (1)
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Calculate the mass of 0.4 moles of calcium (Ca=40)
(Solved)
Calculate the mass of 0.4 moles of calcium (Ca =40)
Date posted:
August 13, 2018
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Answers (1)
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What is the temperature on the Kelvin scale of each of the following? (a) 100°C (b) 22°C
(Solved)
What is the temperature on the Kelvin scale of each of the following? (a) 100°C (b) 22°C
Date posted:
August 13, 2018
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Answers (1)
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Why is the boiling point of propanol higher than that of pentane?
(Solved)
Why is the boiling point of propanol higher than that of pentane?
Date posted:
August 13, 2018
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Answers (1)
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A form 4 student carried out an experiment with 40 cubic centimeters of 1.0M hydrochloric acid and Marble...
(Solved)
Rates and reactions:
A form 4 student carried out an experiment with 40 cubic centimeters of 1.0M hydrochloric acid and Marble chips in order to determine rates of reaction using the following steps.
??HCL was poured to a conical flask
??Conical flask was then placed on a weighing balance
??20 grams of marble chips was then added to acid and left for reaction to proceed
??With time, Changes in mass of flask with contents was recorded
(a) State other way in which one can measure rate of reacion(1mk)
(b)(i) Sketch curve that will be obtain if mass of contents in flask is plotted against time label it as (k) (2mks)
(ii) Using the same axes sketch curve that will be obtain if powdered marble had been used(1mk)
(c) Write a chemical equation to show how reaction proceed (1mk)
Date posted:
August 13, 2018
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Answers (1)