To determine the quantity of pure CaCl2 from the given amount of CaCl2.9H2O, we use the ratio of CaCl2 to CaCl2.9H2O. From the formula the ratio would 1 is to 1 We calculate as follows:
7.5 g CaCl2.9H2O (1 mol / 273.1215 g) ( 1 mol CaCl2 / 1 mol CaCl2.9H2O ) ( <span>110.98 g / 1 mol ) = 3.05 g CaCl2
Hope this answers the question. Have a nice day. Feel free to ask more questions.</span>
Answer:
0.01M
Explanation:
Given paramters:
Volume of FeCl₂ = ?
Concentration = 0.945M
Number of molecules of O₂ = 4.32 x 10²¹molecules
Solution:
The balanced reaction equation is given below:
4FeCl₂ + 3O₂ → 2Fe₂O₃ + 4Cl₂
Now, to solve the problem we use mole relationship between the compounds.
We work from the known to the unknown compounds. Here, the known is the oxygen gas because from the given parameters we can estimate the number of moles of the reacting gas.
number of moles of O₂ = 
number of moles of O₂ = 
number of moles of O₂ = 0.007mole
now, from the reaction equation we find the number of moles of the FeCl₂:
3 mole of O₂ reacted with 4 moles of FeCl₂
0.007mole of O₂ reacted with 
= 0.0096mole O₂
Now to find the volume of FeCl₂ we use the expression below;
volume of FeCl₂ = 
= 
= 0.01L
Answer:
B. Contains more matter
Explanation:
The answer is C because it makes sense to me and a golf ball does contain more matter than a tennis ball
Sorry if I'm wrong :(
Answer:
The student failed to rinse the buret with KMnO₄ solution after rinsing it with distilled water.
Explanation:
In a titration, the equivalent moles of titrant must be the same than analyte. If the student calculates an amount of moles of H₂O₂ that is larger than the actual value:
The student failed to wear goggles <em>FALSE. </em>The use of goggles doesn't change the results in the lab but you must use it!
The student did not swirl the flask appropriately and therefore stopped short of the endpoint. <em>FALSE. </em>The stopped short of the endpoint would explain a lower concentration of the real value.
The student failed to rinse the buret with KMnO₄ solution after rinsing it with distilled water. <em>TRUE. </em>If you don't rinse the buret with KMnO₄ solution the concentration of this solution in the buret will be lower than real concentration doing you spend more titrant volume overestimating the amount of H₂O₂ moles.
The student added an extra 15 mL of distilled water to the H₂O₂ solution. <em>FALSE. </em>The addition of water doesn't change the amount of H₂O₂ moles in the solution.
I hope it helps!
