Answer:
The amount of heat absorbed is <u>5.183889 kJ</u> .
Explanation:
In conversion of water to ice it rejects some heat while in conversion of ice to water it absorbs heat which is called latent heat which is given as 6.02 kJ/mol.
The amount of ice given is 15.5 g.
Converting it to moles as the latent heat is given in per moles:
Molecular mass of Hydrogen (H) and Oxygen (O) is 1 u and 16 u respectively.
Molecular mass of water is 18 g ( 
⇒ 2*1+16=18 ).
mole = 15.5/18 ≈ 0.8611 moles
Therefore the amount of heat absorbed by 15.5 g of ice ( 0.8611 moles) = <em>Latent heat * moles
</em>
Heat absorbed = 6.02*0.8611
= 6.02*(15.5/18)
≈ 5.183889 kJ
Answer:
joules
Explanation:
it is the measurement of energy
c) the salt solubility decreases with temperature.
Salts usually dissolve in water at a given temperature. When water cannot dissolve anymore salt at that same temperature, it is known as a saturation point. With most substances the solubility increases with increase in temperature. Same is the case for a salt like potassium nitrate. With increase in temperature the ability of it to dissolve in water increases. And so with decrease in temperature, the solubility decreases.
Answer: Chemical change
Explanation:
Physical change is a change in which there is no rearrangement of atoms and thus no new substance is formed. There is only change in physical state of the substance. The change can be reversed using physical methods.
Chemical change is a change in which there is rearrangement of atoms and thus new substance is formed. There may or may not be a change in physical state. The change can only be reversed using chemical methods.
Thus when iron and sulfur are heated in a test tube, the chemical change occurs and thus lead to formation of new substances which could not be separated using magnet.
Answer:
Equation of reaction:
a) 2HCl + Ba(OH)2 ==> CaCl2 + 2H2O
b) Molarity of base = 0.042 M.
Explanation:
Using titration equation
CAVA/CBVB = NA/NB
Where NA is the number of mole of acid = 2
NB is the number of mole of base = 1
CA is the molarity of acid =0.15M
CB is the molarity of base = to be calculated
VA is the volume of acid = 25 ml
VB is the volume of base = 44.45mL
Substituting
0.15×25/CB×44.45 = 2/1
Therefore CB =0.15×25×1/44.45×2
CB = 0.042 M.
