Answer:
D) 2, 4, and 5
Explanation:
In order to fully comprehend the answer choices we must take a close look at the value of ΔH° = 31.05. The enthalpy change of the reaction is positive. A positive value of enthalpy of reaction implies that heat was absorbed in the course of the reaction.
If heat is absorbed in a reaction, that reaction is endothermic.
Since ∆Hreaction= ∆H products -∆H reactants, a positive value of ∆Hreaction implies that ∆Hproducts >∆Hreactants, hence the answer choice above.
Answer:
the ion present in the original solution is Ca2+
Explanation:
Precipitation reactions occur when cations and anions in aqueous solution combine to form an insoluble ionic solid called a precipitate.
<u>Step1</u> : If we add Nacl to the solution, there is no precipitate formed
⇒The only possible ion that can form a precipate with Cl- is Ag+; since there is no precipitate formed, Ag+ is not present
<u>Step2</u> : If we add Na2SO4 to the solution, a white precipitate is formed
The possible ions to bind at SO42- are Ca2+ and Fe2+
But the white precipitate formed, points in the direction of Ca2+
⇒This means calcium is present
<u>Step3</u> : If we add Na2CO3 to the filtered solution, there is a precipate formed
Ca2+ will bind also with CO32- and form a precipitate
So the ion present in the original solution is Ca2+
The equation for the reaction between the calcium nitrate and chromium sulfate to form calcium sulfate and chromium(iii) nitrate is,
3Ca(NO3)2 + Cr2(SO4)3 --> 3CaSO4 + 2Cr(NO3)3
The balanced equation shows that for every 1 mole of chromium sulfate, there will be 3 moles of calcium nitrate. Therefore for this item, there will be 4.55 moles times 3 which is equal to 13.65.
<h3>Answer:</h3>
C6H12O6
Explanation:
To find empirical formular you write out the element
Carbon Hydrogen Oxygen
3.96 769 5.28
then u althrough divide by their atomic numbers
3.96÷ 12 769÷1 5.28÷16
=0.33 =769 =0.33
also divide althrough by the lowest number
the lowest number is 0.33 so we use it to divide
0.33÷0.33. 769÷0.33. 0.33÷0.33
= 1 = 2 = 1
empirical formular= CH2O
To find the Molecular formular
Molecular number = molar mass
(CH2O)n = 182
(12+1×2+16)n = 182
30n = 182
n = 6
therefore the Molecular formular is C6H12O6
