Please help on questions 1-9, thank you! 1. Given the following experimental dat

Question

Please help on questions 1-9, thank you!

1. Given the following experimental data:

How much of the zinc reacted?

I got .34g?

2.

Given the following experimental data and referring back to question 1( for mass of reacted Zn):

Calculate the following:

(a). moles of Zn -   

(b). moles of I -

( Answer should be in scientific notation to three significant figures, please use "E" when writing scientific notation).

I got 5.50E-3 for both?

3. Using your answers in , in question 2, what is the empirical formula fo zinc iodide from this experimental data?

Is it ZnI?

4.

Using the empirical formula, in question 3, balance the following equation:

____ Zn(s)   + ____ I2(s)   ----> ___ ZnxIy(s)

What is the sum of the coefficents in the balance chemical equation?

So would it be 5?

5.

Given the following experimental data and data from question 1:

Calculate the percentage difference between mass of the product and mass of the reactant.

( Note: If percentage is negative, take the absolute value of it when answering the question)

I got 21%?

6.

Identify the type or types of reactions the reaction between zinc and iodine is/are.

double displacement reaction

acid base reaction

redox reaction

precipitation reaction

combustion reaction

synthesis reaction

halogen replacement reaction

single replacement reaction

I got redox and synthesis?

7.

Given the percentage difference calculated in question 5, which of the following explanations would be the most logical reason for the error in the experiment?

The student accidentally weighed out more iodine than what was recorded. Causing the mass of product to be more than what was expected.

The student accidentally forgot to cover the top of the Erlenmeyer flask when heating the iodine solution causing some of the iodine to be removed from the solution. Causing the mass of product to be less than what was expected.

No error, the reaction was successfully completed.

The student accidentally put to much methanol in the Erlenmeyer flask when heating the iodine. Causing the mass of product to be less than what was expected.

e. The student accidentally forgot to place the zinc iodide product in a desiccator which allowed for the product to absorb water. Causing the mass of product to be more than what was expected.

8.

How was a student able to identify that the reaction between zinc and iodine was completed?

the solution turning to a pale yellow solution

the formation of a grayish white percipitate

the solution changing to a dark purple colored solution

after all the methanol had evaporated

all the zinc metal disappeared from the solution

9.

Using the figure below:

What process is occurring as iodine solid is transformed into iodine vapor?

sublimation

condensation

melting

deposition

evaporation

condensation

sedimentation

I got sublimation?

Before Reaction Massof empty Erlenmeyer flask 85.35g Mass of Zn and Erlenmeyer flask 86.90g Mass of iodine 1.65g After Reaction Mass of Erlenmeyer flask and unreacted zinc 86.56g

Explanation / Answer

1. Before reaction, mass of zein = 86.9-85.35 = 0.55 g

After reaction, mass of zein = 86.56-86.35 = 0.21 g

Therefore, Zn reacted = 0.55-0.21 = 0.34 g.

2. MOlecular weight of Zn = 65.38

Therefore, number of moles of zinc reacted = 0.34/65.38 g = 5.2 E-3

Molecular weight of iodine = 126.90

Considering that there is no more iodine remaining after reaction,

number of moles of iodine reacted = 1.65/253.8 = 6.5 E-3

3. Mole ratio of Zn : iodine = 5.2 E-3 : 6.5 E-3 = 1: 1.25 which can be approximated to round figure 1:1.

This means 1 mole of Zn reacts with 1 mole of iodine. Since there are two atoms in 1 iodine molecule, the empirical formula will be ZnI2

4. Balanced chemical equation is Zn + I2 = ZnI2.

Sum of the coefficients = 1+ 1 +1 = 3.

5. Mass of the reactant = Initial mass of zinc + initial mass of iodine = 0.55 + 1.65 = 2.2 g

Mass of the product = 1.75 g

Mass loss = 2.2-1.75 = 0.45 g

% loss = (0.45/2.2)*100 = 20.45%

6. Redox reaction, as oxidation state of Zinc changes from 0 to +2 (oxidation) and that of iodine changes from 0 to -1 (reduction).

Synthesis, as multiple reactants combine to give single product.

7. option b, as iodine is highly volatile.

8. option a.

The solution will turn pale yellow, only when there is no more iodine. After all iodine is consumed, there is no more reaction going on. Therefore reaction is complete.

9. option a, as direct conversion from solid to gas (vapor) is called sublimation.

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