Answer and Explanation:
<em>A funnel is in the top of the buret and a beaker is positioned underneath the buret:</em> This is correct and is necessary to fill the buret, but the funnel and the beaker has to be removed before the titration starts. The calculation for moles of analyte does not affect.
<em>A solution is being poured from a bottle into the buret via the funnel:</em> Using a funnel helps to fill the burette but it must be removed to filling the buret at 0.0 mL. In this case, the calculation for moles of analyte do not affect.
<em>Adding titrant past the color change of the analyte solution</em>: In this case, an excess of titrant is added, thus the calculation for moles of anality will be higher than it should be.
<em>Recording the molarity of titrant as 0.1 M rather than its actual value of 0.01 M</em>: In this case, the titrant is considered more concentrated than it is hence, the calculation for moles of anality will be higher than it should be.
<em>Spilling some analyte out of the flask during the titration</em>: The excess of titrant spilled out of the flask higher up the volume of titrant measured. Therefore, the calculation for moles of anality will be higher than it should be.
<em>Starting the titration with air bubbles in the buret</em>: The air inside the burette occupies measured volume, thus the volume of titrant measured will be higher than the real volume spilled in the flask. Hence the calculation for moles of anality will be higher than it should be.
<em>Filling the buret above the 0.0 mL volume mark</em>: Some volume of titrant will be spilled inside the flask but will no be measured since the buret measures the titrant below the 0.0mL mark, thus the calculation for moles of anality will be lower than it should be.
Answer:
q = -176kJ
Explanation:
HCl and NH3 reacts as following to NH4Cl
HCl(g) + NH3(g)=========>NH4Cl(s) : ΔH = -176 KJ
Clearly,
ENERGY IS EVOLVED MEANING IT IS A EXOTHERMIC REACTION .
therefore, the value of heat evolved as q = -176kJ
Answer:- 
molecules.
Solution:- The grams of tetrabromomethane are given and it asks to calculate the number of molecules.
It is a two step unit conversion problem. In the first step, grams are converted to moles on dividing the grams by molar mass.
In second step, the moles are converted to molecules on multiplying by Avogadro number.
Molar mass of 
= 12+4(79.9) = 331.6 g per mol
let's make the set up using dimensional analysis:
= molecules
So, there will be molecules in 250 grams of .
A volumetric flask is used to contain a predetermined volume of substance and only measures that volume, for example 250 ml.
Conical flasks can be used to measure the volume of substances but the accuracy they provide is usually up to 10ml. Conical flasks are used in titrations, reactions where the liquid may boil, and reactions which involve stirring.
Pippettes are of two types, volumetric and graduated. Pippettes are used where high accuracy is required and volumetric pippettes come in as little as 1 ml. Pippettes are usually used in titrations.
Graduated cylinders come in a wide variety of sizes and their accuracy can be down to as much as 1 ml. They are used to contain liquids.
Answer : The number placed in front of 
should be, three (3).
Explanation :
Balanced chemical reaction : It is defined as the number of atoms of individual elements present on reactant side must be equal to the product side.
The given unbalanced chemical reaction is,
This chemical reaction is an unbalanced reaction because in this reaction, the number of atoms of chloride and sulfate ion are not balanced.
In order to balanced the chemical reaction, the coefficient 3 is put before the , the coefficient 2 is put before the 
and the coefficient 3 is put before the 
.
Thus, the balanced chemical reaction will be,
Therefore, the number placed in front of should be, three (3).
