Answer:
chemical change it is melted down
Boiling water is a physical change, because it is changing state of matter, there is a controllable temperature change, and you can change it back.
Frying the egg white is a chemical change, because there is a change of matter, controllable temperature change, but you CAN'T change it back.
The balanced equation for the reaction is as follows
Na₂CO₃ + 2HCl --> 2NaCl + CO₂ + H₂O
stoichiometry of Na₂CO₃ to HCl is 1:2
number of Na₂CO₃ moles reacted = molarity x volume
number of Na₂CO₃ moles = 0.100 mol/L x 0.750 L = 0.0750 mol
according to molar ratio of 1:2
1 mol of Na₂CO₃ reacts with 2 mol of HCl
then 0.0750 mol of Na₂CO₃ mol reacts with - 2 x 0.0750 = 0.150 mol
molarity of given HCl solution is 1.00 mol/L
molarity is defined as the number of moles of solute in 1 L of solution
there are 1.00 mol in 1 L of solution
therefore there are 0.150 mol in - 0.150 mol / 1.00 mol/L = 0.150 L
volume of HCl required is 0.150 L
The Lewis Structure of HCN is shown below,
Number of Bonding Electrons: In HCN Hydrogen is bonded to Carbon through single bond and Nitrogen is bonded to Carbon through Triple Bond. Single bond is formed by two bonding electrons, while, triple bond is formed by six bonding electrons, Hence,
Number of Bonding Electrons = 8
Number of Non-Bonding Electrons:
In HCN there is only one lone pair of electron present on Nitrogen atom which is not taking part in bonding. Hence,
Number of Non-Bonding Electrons = 2
Result: Number of Bonding Electrons = 8 Number of Non-Bonding Electrons = 2