Answer:
kJ/mol
Explanation:
Given and known facts
Mass of Benzene 
grams
Mass of water 
grams
Standard heat capacity of water 
J/g∙°C
Change in temperature ΔT 
°C
Heat
Heat released by benzine is - 7.82 kJ
Now, we know that
grams of benzene release 
kJ heat
So, 
g benzine releases
kJ/g
mol C6H6
Heat released
kJ/mol
<h3><u>Answer;</u></h3>
10.80 ° C
<h3><u>Explanation;</u></h3>
From the information given;
Initial temperature of water = 24.85°C
Final temperature of water = 35.65°C
Mass of water = 1000 g
The specific heat of water ,c = 4.184 J/g °C.
The heat capacity of the calorimeter = 695 J/ °C
Change in temperature ΔT = 35.65°C - 24.85°C
= 10.80°C
Answer:
The proportion of dissolved substances in seawater is usually expressed in ppm, ppb or ppt
Explanation:
The concentration of very diluted solutions should be expressed in parts per million, billion or trillion.
ppm = mass from the solute . 10⁶ / mass or volume of the solution
ppb = mass from the solute . 10⁹ / mass or volume of the solution
ppt = mass from the solute . 10¹² / mass or volume of the solution
ppm = mg/kg, μg/g, μg/mL → These are the units
ppb = ng/g
ppt = pg/g
<u>Answer:</u>
<em>Silver tarnishing as the silver metal reacts with sulphur is a chemical change.</em>
<u>Explanation:</u>
Tarnishing is the process of chemical change occurring on the surface of objects leading to corrosion or other defects on the surface. The remaining options like dilution, eroding is a physical change where the concentration of salt and rock particles will be decreased, respectively.
Similarly for soil drying also the concentration of water will be decreased leading to a physical change from wetty or dry soil.
But the last option which indicates tarnishing of silver metal on reaction with sulphur is a chemical process as the surface of silver metal will be reacting to sulphur and leads to lose of electrons which leads to corrosion of the surface or tarnishing of silver.
