Answer:
it is an organic molecule
Explanation:
it's a compound called chromium, phosphate tetrahydrate, where tetra stands for 4 , as there are four water molecules attached to the compound.
Ponds are most likely to dry up
Chemical reactions can be broadly classified into two categories from the context of heat requirement. These include; endothermic and exothermic reactions.
Endothermic reactions proceed with the absorption of heat while exothermic reactions are accompanied by the evolution of heat.
1) Oxidation of iron involves reaction of elemental iron with oxygen to form iron oxide (rust). This is essentially a corrosion reaction in which the metallic bonds in Fe are broken and new bonds between Fe and O are formed, This is an exothermic reaction
4Fe + 3O2 → 2Fe2O3
Ans D)
2) The process of condensation i.e. phase change liquid to solid (or gas to liquid) involves release of heat to the surroundings, hence it will be an exothermic reaction.
Ans B)
3) Specific heat is the amount of heat required to raise the temperature of 1 g of a substance by a 1 C. Typically, liquids and gases are used as coolants. For a coolant to be efficient, it must have a high specific heat.
Ans B)
Answer: The energy of combustion of butter is 31.5 kJ/g
Explanation:
The quantity of heat required to raise the temperature of a substance by one degree Celsius is called the specific heat capacity.
Q = Heat absorbed by calorimeter =?
C = heat capacity of calorimeter = 
Initial temperature of the calorimeter = 
= 
Final temperature of the calorimeter = 
= 
Change in temperature ,
Putting in the values, we get:
As heat absorbed by calorimeter is equal to heat released by combustion of butter
Heat released by 0.22 g of butter = 6.94 kJ
Heat released by 1g of butter = 
The energy of combustion of butter is 31.5 kJ/g
Explanation:
Part A
Boiling point of HF is much higher as compared to the boiling point of HCl.
Reason:
The strongest inter molecular hydrogen bonding exist between HF molecules This is due to highly electronegative Fluorine atom.
Part B
The type of bonding present in the given compounds are:
1. Ice
The water molecules in ice are linked to each other through intermolecular hydrogen bonding due to the presence of electronegative oxygen atom that is attached to hydrogen atom.
2. Copper dioxide
In Copper dioxide, Copper and oxide ions are linked to each other via electrostatic force of attraction due to the presence of electronegative Oxygen atom and electropositive Cu atom.
Therefore, ionic bond is present in it.
3. Steel
In steel, metal and negatively charged electrons are linked to each other, thus giving rise to metallic bond between steel molecules.
4. Silicon elastomer
In silicon elastomer, Silicon atom is linked to other atom via covalent bonds due to sharing of electrons.
5. Tungsten
In the case of tungsten also, atoms are bonded to each other via metallic bond.
