All categories

3 years ago

How to calculate percent error of a melting point range?

Chemistry

1 answer:

olya-2409 [2.1K]3 years ago

5 0

Answer:

3.9%

Explanation:

Exact melting point = 123°C

Measured melting point = 128°C

% error; |measured - exact|/exact × 100

% error = |123 -128|/128 × 100

%error = 3.9%

Percentage error in temperature measurement = 3.9 %

You might be interested in

If 125 mg of Ar(g) is added to a 505-mL sample of Ar(g) at STP, what volume will the sample occupy when the conditions of STP ar

miss Akunina [59]

Answer:

The new volume will be 575 mL

Explanation:

Step 1: Data given

Mass of Ar = 125 mg = 0.125 grams

Volume = 505 mL = 0.505 L

Molar mass Ar = 39.95 g/mol

Step 2 : Calculate moles of Ar to start

n = PV/RT

⇒ with n = initial number of moles Ar

⇒ with p = pressure = 1.0 atm

⇒ with R = the gas constant = 0.08206 L* atm/mol *K

⇒ with V = the volume = 0.505 L

⇒ with T = the temperature = 273.15 K

n = 0.505 L * 1 atm / (0.08206 * 273.15 deg K) =0.02253 moles

Step 3: Calculate add moles of Ar

Moles Ar = mass Ar / molar mass Ar

Moles Ar = 0.125 g / 39.95 g/mol = 0.00313 moles

Step 4: Calculate total moles Ar

Total moles Ar = 0.02253 + 0.00313 = 0.02566 moles

Step 5: Calculate new volume

V = nRT/P

V = 0.02566 * 0.08206 * 273.15 / 1 atm

V = 0.575 L = 575 mL

The new volume will be 575 mL

4 0

3 years ago

Which statement describes the particles of an ideal gas based on the kinetic molecular theory?

Zielflug [23.3K]

Answer:

Well ads I remember, the motion of the gas particles is random and in a straight-line. A sample of gas is contained in a closed rigid cylinder.

And here is what I found too -

According to Kinetic Molecular Theory, gaseous particles are in a state of constant random motion; individual particles move at different speeds, constantly colliding and changing directions. We use velocity to describe the movement of gas particles, thereby taking into account both speed and direction.

8 0

3 years ago

How many moles of Fluorine (F2) are<br><br> needed to completely react 8.0<br><br> moles of NF3?

Anna [14]

Answer:

12 moles of F₂

Explanation:

We'll begin by writing the balanced equation for the reaction. This is illustrated below:

N₂ + 3F₂ —> 2NF₃

From the balanced equation above,

3 moles of F₂ reacted to produce 2 moles of NF₃.

Finally, we shall determine the number of mole of F₂ needed to produce 8 moles of NF₃. This can be obtained as illustrated below:

From the balanced equation above,

3 moles of F₂ reacted to produce 2 moles of NF₃.

Therefore, Xmol of F₂ will react to produce 8 moles of NF₃ i.e

Xmol of F₂ = (3 × 8)/2

Xmol of F₂ = 12 moles

Thus, 12 moles of F₂ is needed for the reaction.

8 0

3 years ago

Calculate the concentration 3.8g of copper sulfate, CuSO4 dissolved in 250cm4 of water

11Alexandr11 [23.1K]

Answer:

Molarity = 0.08 M

Explanation:

Given data:

Mass of copper sulfate = 3.8 g

Volume of water = 250 cm³ (250/1000 = 0.25 L)

Concentration of solution = ?

Solution:

Number of moles of copper sulfate:

Number of moles = mass/molar mass

Number of moles = 3.8 g/ 159.6 g/mol

Number of moles = 0.02 mol

Concentration:

Molarity = Number of moles / volume in L

By putting values,

Molarity = 0.02 mol / 0.25 L

Molarity = 0.08 mol/L

Molarity = 0.08 M

6 0

3 years ago

The density of ice is 0.917 g/cm3. What volume of ice does 52.75 g occupy?

Vadim26 [7]

Answer:

The answer is

Explanation:

The volume of a substance when given the density and mass can be found by using the formula

$volume = \frac{mass}{density}$

From the question

mass of ice = 52.75 g

density = 0.917 g/cm³

The volume of the ice is

$volume = \frac{52.75}{0.917} \\ = 57.52453653$

We have the final answer as

Hope this helps you

4 0

3 years ago