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WorksheetsSEC 1 LESSON 4
Total questions: 20
Worksheet time: 3600secs
What name and sympol is given to the overall change in energy at constant pressure during a chemical reaction.
Potential difference , ΔV
Temprature change , ΔT
Entropy change , ΔS
Which of these statement does not describe the converstion of energy in a chemical reaction ?
Energy is neither created nor destroyed during a chemical reaction.
The energy contained in the bonds of rectant molecules always equal the energy contained in the bonds of the product molecules.
If the energy of the system increase the energyof the surrounding decrease by the exact same amount
Energy can only be transferred from one form to another.
Why do chemical reactions usually involve a change in energy?
The process of making or breaking bonds during a chemical reaction absorbs and releases energy.
The process of splitting the nucleus of an atom releases large amounts of energy.
The nuclei move faster during chemical reactions and so require more energy.
In chemical reactions, atoms are destroyed and converted into energy.
Which of the following is not a type of energy that a chemical reaction may produce?
Light
Electric
Color
Chemical
Fuels can also be used to provide energy. Which of the following fuels does not produce energy through a chemical reaction?
Biofuels
Fuel cells
Nuclear fuel
Fossil fuel
Many chemical reactions are used to provide energy in the form of heat. However, what type of useful energy do the chemical reactions inside batteries provide?
Sound
Electicity
Light
Gravitational
Diphenyl oxalate, hydrogen peroxide, and rhodamine A are mixed together in a plastic tube. After a few seconds, the plastic tube begins to feel warm, and the resulting mixture starts to glow a bright-red colour. Which types of energy are produced by the mixture?
Light only
Heat only
Heat and light
Light and electric
The opposite graphical figure represents the thermal change which occurs during a chemical reaction, What is the value of ∆H of this reaction?
-120kj
-30kj
+30kj
+120kj
The molar bond energy of F2 is 159 kJ/mol.Calculate the energy of one F-F bond
1.65 x 10-19 J
2.64 x 10-19 J
9.58 x 10-19 J
3.78 x 10-19 J
What is Avogadro’s number to 2 decimal places
6.02 x 1023
6.71 x 1014
109
3.14
3.70 mol of Cl-Cl bonds release 888 kJ of energy when they form. How much energy is released when 1000 Cl-Cl bonds form?
3.99 x 10-16
1.48 x10-15 J
3.99 X 10-19 J
1.48 X 10-18 J
Which of the following quantities of bonds requires the most energy to break?
5.8 mol I-I (148 KJ/mol)
2.0 mol H-H (436 KJ/mol)
2.0 mol H-Cl ( 428 KJ/mol)
1.0 mol (835 KJ/mol)
energy of the hydrogen–hydrogen bond in H2 is 436 kJ/mol.Which of the following is an equivalent description of the bond energy in hydrogen
436 kJ of energy is required to form the hydrogen–hydrogen bonds of 6.02×1023 hydrogen molecules.
For every hydrogen–hydrogen bond in a hydrogen molecule formed, 436 kJ of energy is released
436 kJ of energy is required to break the hydrogen–hydrogen bonds of 6.02 x 1023 hydrogen molecules.
For every hydrogen–hydrogen bond in a hydrogen molecule broken, 436 kJ of energy is released.
food manufacturer determines that the energy content of one slice of their new bread is 400 kJ.What value is this in kilocalories?Give your answer to 1 decimal place.
95.6
95
93
94
A chocolate bar is found to contain 228 kcal.What value is this in units of kilojoules?Give your answer to the nearest whole number.
954
956
950
960
When 8 g of ammonium nitrate salt are added to a coffee cup calorimeter which contains 125 g of water whose temperature is 24.2°C, the temperature of the solution drops to 18.2°C, so if the specific heat of the solution is 4.2 J/g.°C, What is the molar heat of the solution? [N=14, H=1, O=16]
+33.5 kJ/mol
+39.5 kJ/mol
+32.2 kJ/mol
+37.3 kJ/mol
In exothermic solution, the value of... is as high as high as possible.
∆H1
∆H2
∆H3
∆H1+∆H2
If you know that the standard heat of solution of potassium iodide salt-equals +14 kJ/mol, which of the following statements is probable to be not correct?
Dissolving salt in water is exothermic.
Hydration energy of ions equals —322 kJ/mol.
Hydration energy of ions equals —293 kJ/mol
Attaching energy of and ions to water is less than the separation energy of these ions in salt.
Why will the measured change in energy always be lower than the total energy transferred?
Some of the energy gets destroyed during the reaction.
There will always be some amount of heat energy lost to the surroundings.
The water will contain impurities that will absorb some of the heat energy.
Not all of the reactants will be used up.
An experiment is carried out using calorimetry to compare the heat released from a range of different fuels. Which of the following factors does not need to be kept constant when repeating the experiment for each different fuel?
Same mass of fuel burnt
Thermometer
Volume of the water
Starting temperature of the water
