All categories

3 years ago

What factors could have affected your results?

Chemistry

1 answer:

AleksandrR [38]3 years ago

8 0

Answer:

See below

Step-by-step explanation:

heat gained by metal + heat lost by water = 0

m₁C₁ΔT₁ + m₂C₂ΔT₂ = 0

C₁ = -(m₂C₂ΔT₂)/(m₁ΔT₁)

The factors determining C₁ are

mass of water
temperature change of water (T_f - Ti)
mass of metal
temperature change of metal (T_f - Ti)

Any factor that makes the numerator higher or the denominator lower than what you thought, will give a calculated C₁ that is too high (and vice versa).

The major sources of uncertainty are probably in determining the temperatures, especially the initial and final temperatures of the metal. However, you will have to decide what the principal factors were in your experiment.

For example, did the metal have a chance to cool during the transfer to the calorimeter? How easy was it to determine the equilibrium temperature, etc?

Factors Affecting the Calculation of Specific Heat Capacity

Water Water

Mass less than thought Mass more than thought

Ti lower Ti higher

T_f higher T_f lower

Metal Metal

Mass more than thought Mass less than thought

Ti higher Ti lower

You might be interested in

171 g of sucrose ( MW of 342, melting point 186 oC, boiling point very high, and vapor pressure is negligible) is dissolved in o

Fantom [35]

The complete question is as follows: 171 g of sucrose ( MW of 342, melting point 186 oC, boiling point very high, and vapor pressure is negligible) is dissolved in one liter of water at 25 oC. At 25 oC the vapor pressure of water is 24 mmHg. Which value is closest to the vapor pressure (VP) of this solution at 25 oC?

a. 16mm Hg

b. 24mm Hg

c. 20mm Hg

d. 12mm Hg

Answer: The vapor pressure (VP) of this solution at $25^{o}C$ is closest to the value 24 mm Hg.

Explanation:

Given: Mass of sucrose = 171 g

Mass of water = 1 L = 1000 g

Vapor pressure of water = 24 mm Hg

As moles is the mass of substance divided by its molar mass. Hence, moles of water (molar mass = 18.02 g) is calculated as follows.

$Moles = \frac{mass}{molar mass}\\= \frac{1000 g}{18.02 g/mol}\\= 55.49 mol$

Similarly, moles of sucrose (molar mass = 342 g/mol) is as follows.

$Moles = \frac{mass}{molar mass}\\= \frac{171 g}{342 g/mol}\\= 0.5 mol$

Total moles = 55.49 + 0.5 mol = 55.99 mol

Mole fraction of water is as follows.

$Mole fraction = \frac{moles of water}{total moles}\\= \frac{55.49}{55.99}\\= 0.99$

Formula used to calculate vapor pressure of the solution is as follows.

$P_{i} = P^{o}_{i} \times \chi_{i}$

where,

$P_{i}$ = vapor pressure of component i over the solution

$P^{o}_{i}$ = vapor pressure of pure component i

$\chi_{i}$ = mole fraction of i

Substitute the values into above formula to calculate vapor pressure of water as follows.

$P_{i} = P^{o}_{i} \times \chi_{i}\\= 24 mm Hg \times 0.99\\= 23.76 \\or 24 mm Hg\\$

Thus, we can conclude that the vapor pressure (VP) of this solution at $25^{o}C$ is closest to the value 24 mm Hg.

4 0

3 years ago

IMMA WAIT FOR MY BABY EVEN IF IT TAKES ALL NIGHT !!!!!!

saul85 [17]

Answer:

um okay lol

Explanation:

3 0

3 years ago

Read 2 more answers

A perfect cube of aluminum metal was found to weigh 20.00 g. The density of aluminum is 2.7 g/ml. What are the dimensions of the

denis23 [38]

Answer:

Height = 1.9493 cm

Width = 1.9493 cm

Depth = 1.9493 cm

Solution:

Data Given:

Mass = 20 g

Density = 2.7 g/mL

Step 1: Calculate the Volume,

As,

Density = Mass ÷ Volume

Or,

Volume = Mass ÷ Density

Putting values,

Volume = 20 g ÷ 2.7 g/mL

Volume = 7.407 mL or 7.407 cm³

Step 2: Calculate Dimensions of the Cube:

As we know,

Volume = length × width × depth

So, we will take the cube root of 7.407 cm³ which is 1.9493 cm.

Hence,

Volume = 1.9493 cm × 1.9493 cm × 1.9493 cm

Volume = 7.407 cm³

4 0

3 years ago

Draw the lewis dot structures for each of the following molecules. show the resonance structures, if they exist

jonny [76]

What dont u understand about lewis dot structures???.
.how to determine the number of dots ..or

5 0

3 years ago

Four flasks are prepared, each containing 100mL of aqueous solutions of equal concentration. Which solution has the lowest freez

Jet001 [13]

The freezing point depression is a colligative property which means that it is proportional to the number of particles dissolved.

The number of particles dissolved depends on the dissociation constant of the solutes, when theyt are ionic substances.

If you have equal concentrations of two solutions on of which is of a ionic compound and the other not, then the ionic soluton will contain more particles (ions) and so its freezing point will decrease more (will be lower at end).

In this way you can compare the freezing points of solutions of KCl, Ch3OH, Ba(OH)2, and CH3COOH, which have the same concentration.

As I explained the solution that produces more ions will exhibit the greates depression of the freezing point, leading to the lowest freezing point.

In this case, Ba(OH)2 will produce 3 iones, while KCl will produce 2, CH3OH will not dissociate into ions, and CH3COOH will have a low dissociation constant.

Answer: Then, you can predict that Ba(OH)2 solution has the lowest freezing point.

6 0

3 years ago