What is the total mass of reactants compared to the total mass of products

How many molecules are in 3 moles of potassium bromide (KBr)

sattari [20]

Answer:

Your strategy here will be to use the molar mass of potassium bromide,

KBr

, as a conversion factor to help you find the mass of three moles of this compound.

So, a compound's molar mass essentially tells you the mass of one mole of said compound. Now, let's assume that you only have a periodic table to work with here.

Potassium bromide is an ionic compound that is made up of potassium cations,

K

+

, and bromide anions,

Br

−

. Essentially, one formula unit of potassium bromide contains a potassium atom and a bromine atom.

Use the periodic table to find the molar masses of these two elements. You will find

For K:

M

=

39.0963 g mol

−

1

For Br:

M

=

79.904 g mol

−

1

To get the molar mass of one formula unit of potassium bromide, add the molar masses of the two elements

M

M KBr

=

39.0963 g mol

−

1

+

79.904 g mol

−

1

≈

119 g mol

−

So, if one mole of potassium bromide has a mas of

119 g

m it follows that three moles will have a mass of

3

moles KBr

⋅

molar mass of KBr



119 g

1

mole KBr

=

357 g

You should round this off to one sig fig, since that is how many sig figs you have for the number of moles of potassium bromide, but I'll leave it rounded to two sig figs

mass of 3 moles of KBr

=

∣

¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯

a

360 g

a

∣

−−−−−−−−−

Explanation:

answer: 360 g 

6 0

3 years ago

Describe the relationship between hydrogen ions (h+) and ph. how is ph related to a solution's acideic

natita [175]

The pH = -log of hydrogen ion concentration

The more acid a solution is the higher is its concentration of H+ ions and the lower is its pH. Acids have a pH lower that 7.

5 0

3 years ago

What is the ground-state electron configuration of a neutral atom of manganese?.

Alchen [17]

Explanation:

elctronic configuration of manganese

Mn=1s²2s²2p⁶3s²3p⁶4s²3d⁵

ground state

Mn=Ar3d⁵4s²

note that Ar is argon

3 0

3 years ago

A piece of wood has a labeled length value of 63.2 cm. You measure its length three times and record the following data: 63.1 cm

Ulleksa [173]

Percent error (%)= $\frac{\left | Accepted value - Measured value \right |}{Accepted value}\times 100$

Accepted value is true value.

Measured values is calculated value.

In the question given Accepted value (true value) = 63.2 cm

Given Measured(calculated values) = 63.1 cm , 63.0 cm , 63.7 cm

1) Percent error (%) for first measurement.

Accepted value (true value) = 63.2 cm, Measured(calculated values) = 63.1 cm

Percent error (%)= $\frac{\left | Accepted value - Measured value \right |}{Accepted value}\times 100$

$Percent error = \frac{\left | 63.2 - 63.1 \right |}{63.2}\times 100$

$Percent error = \frac{0.1}{63.2}\times 100$

$Percent error = 0.00158\times 100$

Percent error = 0.158 %

2) Percent error (%) for second measurement.

Accepted value (true value) = 63.2 cm, Measured(calculated values) = 63.0 cm

Percent error (%)= $\frac{\left | Accepted value - Measured value \right |}{Accepted value}\times 100$

$Percent error = \frac{\left | 63.2 - 63.0 \right |}{63.2}\times 100$

$Percent error = \frac{0.2}{63.2}\times 100$

$Percent error = 0.00316\times 100$

Percent error = 0.316 %

3) Percent error (%) for third measurement.

Accepted value (true value) = 63.2 cm, Measured(calculated values) = 63.7 cm

Percent error (%)= $\frac{\left | Accepted value - Measured value \right |}{Accepted value}\times 100$

$Percent error = \frac{\left | 63.2 - 63.7 \right |}{63.2}\times 100$

$Percent error = \frac{\left | -0.5 \right |}{63.2}\times 100$

$Percent error = \frac{(0.5)}{63.2}\times 100$

$Percent error = 0.00791\times 100$

Percent error = 0.791 %

Percent error for each measurement is :

63.1 cm = 0.158%

63.0 cm = 0.316%

63.7 cm = 0.791%

7 0

4 years ago

Review the equation below. 2KClO3 mc012-1.jpg 2KCl + 3O2 How many moles of oxygen are produced when 2 mol of potassium chlorate

Vlada [557]

Stoichiometry of the reaction:

2 KClO₃ = 2 KCl + 3 O₂
 ↓ ↓

2 mole KClO₃ ----------> 3 mole O₂
2 mole KClO₃ ----------> ?

KClO₃ = 2 * 3 / 2

KClO₃ = 6 / 2

= 3 moles de KClO₃

hope this helps!

4 0

3 years ago

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