Chemistry and Energy

The inherent energy of matter that transforms into heat during chemical reactions is called:

Atoms remain connected to one another by means of:

The energy by which atoms remain joined with another atom in a chemical bond is called:

In sodium chloride, the bond between sodium ion and chloride ion is:

In carbon dioxide, the bond between carbon and oxygen is:

In iron, atoms are bonded together due to:

Which of the following correctly defines bond energy?

Bond energy of $\ce{O=O}$ is:

Bond energy of $\ce{C-H}$ is:

Bond energy of $\ce{C-Cl}$ is:

Bond energy of $\ce{C-C}$ is:

Bond energy of $\ce{C=C}$ is:

Bond energy of $\ce{C#C}$ (triple) is:

Bond energy of $\ce{N#N}$ is:

Bond energy of $\ce{Cl-Cl}$ is:

Bond energy of $\ce{Br-Br}$ is:

Bond energy of $\ce{I-I}$ is:

Bond energy of $\ce{H-H}$ is:

Bond energy of $\ce{N-H}$ is:

Bond energy of $\ce{O-H}$ is:

Bond energy of $\ce{H-Cl}$ is:

Bond energy of $\ce{H-Br}$ is:

Bond energy of $\ce{H-I}$ is:

Bond energy of $\ce{H-F}$ is:

Bond energy of $\ce{C=O}$ is:

Bond energy of $\ce{C-O}$ is:

Bond energy of $\ce{O-O}$ is:

To break one $\ce{O=O}$ bond, the heat required is:

Forming one $\ce{O=O}$ bond evolves:

Which has the highest single-bond energy among halogens with hydrogen?

The energy that keeps molecules of a covalent compound combined with each other is:

In water, surrounding molecules are combined to a central water molecule by:

In sodium chloride, how many chloride ions surround a sodium ion?

In sodium chloride, how many sodium ions surround a chloride ion?

Compared to inter molecular energy of covalent molecules, the attraction energy between ions of an ionic compound is:

Why do ionic compounds have higher melting and boiling points than covalent compounds?

At room temperature, ionic compounds usually exist as:

At room temperature, covalent compounds usually exist in:

Which covalent compound is an exception that remains solid at room temperature?

Compared to inter molecular energy in $\ce{H2}$, the inter molecular energy in $\ce{HCl}$ is:

Energy of reactants needed to make a reaction occur or energy released from a reaction may be in the form of:

The unit earlier used to measure energy was:

The heat applied to raise the temperature of 1 gram of water by 1°C is called:

1 kilocalorie equals:

The international standard unit to measure energy is:

A joule is the work done by a force of:

1 kJ equals:

1 calorie equals approximately:

1 kcal equals approximately how many joules?

Reactions in which heat is evolved are called:

Reactions in which heat is absorbed are called:

In exothermic reactions, the value of ΔH is:

In endothermic reactions, the value of ΔH is:

The internal energy of a substance at a specific temperature is denoted by:

ΔH equals:

In an exothermic reaction:

In an endothermic reaction:

If reactant internal energy is 50 kJ/mol and product internal energy is 20 kJ/mol, ΔH equals:

If reactant internal energy is 70 kJ/mol and product internal energy is 80 kJ/mol, ΔH equals:

Burning of methane produces how many kJ per mole?

The reaction $\ce{CH4 + 2O2 -> CO2 + 2H2O}$ has ΔH equal to:

When water is poured on dry lime $\ce{CaO}$, calcium hydroxide is formed and how much heat is produced?

The reaction $\ce{CaO + H2O -> Ca(OH)2}$ is:

The decomposition of $\ce{CaCO3}$ to $\ce{CaO}$ and $\ce{CO2}$ requires how much heat?

The reaction $\ce{CaCO3 -> CaO + CO2}$ has ΔH equal to:

The reaction of preparing edible lime from snail/oyster shells is:

Snail shells contain about what percentage of calcium carbonate?

In an exothermic reaction equation, the word "Heat" is written:

In an endothermic reaction equation, the heat term may appear:

ΔH using bond energies equals:

Energy required to break bonds is:

Energy released when new bonds form is:

In an exothermic reaction, the relation between $B_r$ (bond energy of reactants) and $B_p$ (bond energy of products) is:

In an endothermic reaction, the relation between $B_r$ and $B_p$ is:

For the reaction $\ce{CH4 + Cl2 -> CH3Cl + HCl}$ given $\ce{C-H}=414$, $\ce{Cl-Cl}=244$, $\ce{C-Cl}=326$, $\ce{H-Cl}=431$ kJ/mol, total energy to break bonds in reactants:

For the same reaction, total bond energy released forming products:

ΔH for the reaction $\ce{CH4 + Cl2 -> CH3Cl + HCl}$ is:

The reaction $\ce{CH4 + Cl2 -> CH3Cl + HCl}$ is:

ΔH calculated by internal energy method versus by bond energy method:

Chemical energy can transform into:

When wood/natural gas/coal is burnt, the energy primarily obtained from:

Burning is essentially the reaction of a substance with:

The main ingredient of natural gas is:

Fireworks emit light, sound and:

The batteries used in torches and remotes are:

The batteries used in buses and trucks are:

In a Daniell cell, the metal stick used in $\ce{ZnSO4}$ solution is:

In a Daniell cell, the metal stick used in $\ce{CuSO4}$ solution is:

The reaction in a Daniell cell is:

The Daniell cell transforms chemical energy into:

Chemical energy is the most used form of energy among:

Heat from burning wood is used for:

Industries that require huge amount of heat include:

Mineral fuels are burnt in burning chambers of heat engines to produce heat which is converted to:

Chlorophyll helps plants utilize:

Photosynthesis produces glucose ($\ce{C6H12O6}$) and:

The sunlight participating in photosynthesis remains stored in plants as:

Without chemical energy:

Petroleum, coal and natural gas are called:

Burning fossil fuels yearly produces approximately how many billion tons of $\ce{CO2}$?

$\ce{CO2}$ is a:

$\ce{CO2}$ reacts with rain water to produce:

Excessive use of fossil fuels will:

Acid rain is harmful to:

Burning fuel in insufficient air produces:

Carbon monoxide is:

Natural fuels are of crude form and contain compounds of:

If unrefined fuel is burnt, oxides of N/S/P enter air and form:

The reaction $\ce{CO2 + H2O -> H2CO3}$ produces:

Sulfur dioxide and oxygen react to form:

Sulfur trioxide and water react to form:

The reactions of $\ce{NO2}$/$\ce{SO3}$ with water produce nitric acid involving:

Smoke from automobiles consists of:

In presence of sunlight, automobile smoke gases react to form:

Acid rain in water bodies makes survival of fishes:

Trees take in $\ce{CO2}$ during:

About what fraction of yearly produced $\ce{CO2}$ remains on earth?

$\ce{CO2}$ is a heavy gas and:

The increase of earth's temperature due to greenhouse gases is called:

The phenomenon of heat-trapping by greenhouse gases is called:

Global warming melts polar ice and causes sea level to:

Which country among the following is at risk of being submerged due to sea level rise?

The other name of ethanol is:

The formula of ethanol is:

All automobiles in USA use fuel mixed with what percentage of ethanol?

Burning ethanol produces:

Ethanol may be a suitable substitute for:

The mechanism that converts chemical energy directly into electrical energy or uses electrical energy to conduct chemical reactions is:

Electrochemical cells are of how many kinds?

The cell in which electricity from an outer source is used to carry out a chemical reaction is:

The cell in which a chemical reaction produces electricity is:

Conductors are of how many types based on the mechanism of passage of electricity?

Substances through which electricity is passed by means of electrons are:

Which of the following is an electronic conductor?

Graphite is an electronic conductor because:

Substances that conduct electricity in molten/solution state but not in solid state and undergo chemical change are:

Which of the following is an electrolyte?

Strong electrolytes are completely ionized in:

Which is a strong electrolyte?

Which of the following is a weak electrolyte?

Pure water is a:

Sulfuric acid ($\ce{H2SO4}$) is a:

An electrode is:

In an electrochemical cell, the electrode where oxidation occurs is:

The electrode where reduction occurs is:

In oxidation at an electrode, the species:

Positive ions accept electrons at the:

Electrolysis of molten sodium chloride produces at the anode:

Electrolysis of molten sodium chloride produces at the cathode:

Overall reaction of electrolysis of molten NaCl:

In molten NaCl, the migrating species are:

The anode in electrolysis is connected to which terminal of the battery?

The cathode is connected to which terminal of the battery?

At the anode of molten NaCl electrolysis:

At the cathode of molten NaCl electrolysis:

The ion attracted by the cathode is called a:

The ion attracted by the anode is called a:

Wet blue litmus paper held over chlorine gas turns:

$\ce{Cl2}$ + $\ce{H2O}$ produces:

The blue litmus turns red because of:

In concentrated NaCl solution, additional ions present besides $\ce{Na+}$ and $\ce{Cl-}$ are:

At the cathode in NaCl solution electrolysis, which is reduced first?

The reaction at the cathode of NaCl solution electrolysis:

At the anode of NaCl solution electrolysis, the species discharged earlier than $\ce{OH-}$ is:

Why does $\ce{Cl-}$ discharge before $\ce{OH-}$ in NaCl solution electrolysis even though $\ce{OH-}$ is lower in the series?

The species left behind in NaCl solution electrolysis combine to form:

Three factors that determine which ion discharges first are: tendency, concentration and:

The reactivity series of metals is also called:

Between two metals in the electrochemical series, the metal placed above is:

Between two metal ions, the ion of the metal at lower order will:

Between $\ce{Na+}$ and $\ce{H+}$, which discharges first at cathode?