That it is below the lithosphere and it is the remainder of the mantle or lower mantle
Answer: The correct option is b.
Explanation: Chemical reaction is a reaction i which the chemical composition of the reactants gets changed and new substances having different chemical composition is formed. This reaction cannot be reversed by any physical means.
Indicators showing chemical changes are :
- Color change
- Characteristic odor
- Formation of bubbles
- Formation of precipitate
From the given information above, it can be stated that the correct option is b.
<u>Given:</u>
Mass of ice = mass of water = 5.50 kg = 5500 g
Temperature of ice = -20 C
Temperature of water = 75 C
<u>To determine:</u>
Mass of propane required
<u>Explanation:</u>
Heat required to change from ice to water under the specified conditions is:-
q = q(-20 C to 0 C) + q(fusion) + q (0 C to 75 C)
= m*c(ice)*ΔT(ice) + m*ΔHfusion + m*c(water)*ΔT(water)
= 5500[2.10(0-(-20)) + 334 + 4.18(75-0)] = 3792 kJ
The enthalpy change for the combustion of propane is -2220 kJ/mol
Therefore, the number of moles of propane corresponding to the required energy of 3792 kJ = 1 mole * 3792 kJ/2220 kJ = 1.708 moles of propane
Molar mass of propane = 44 g/mol
Mass of propane required = 1.708 moles * 44 g/mol = 75.15 g
Ans: 75.15 grams of propane must be combusted.
When the solution used begins to change color and stays the new color for at least 30 seconds we are able to tell that the solution has reached the end point of titration
