All categories

3 years ago

How many moles are equal to a 0.25g sample of chromium?

Chemistry

1 answer:

jonny [76]3 years ago

7 0

Answer:

0.0048 mol Cr

Explanation:

Step 1: Define

Molar Mass of Chromium (Cr) - 52.00 g/mol

Step 2: Use Dimensional Analysis

$0.25 \hspace{3} g \hspace{3} Cr(\frac{1 \hspace{3} mol \hspace{3} Cr}{52.00 \hspace{3} g \hspace{3} Cr} )$ = 0.004808 mol Cr

Step 3: Simplify

We are give 2 sig figs.

0.004808 mol Cr ≈ 0.0048 mol Cr

You might be interested in

Look at the equation for the reaction for nitric oxide and oxygen. Do you think this is a single-step reaction or a multistep re

Sveta_85 [38]

Answer:

This is most likely a multi-stepped reaction.

Explanation:

From the collision theory, we know that it is super improbable for 3 different molecules (2 NO and 1 O2) to all hit each other at the perfect speed in the perfect position to make the products. From this, we can pretty confidently say that this is most likely a multi-stepped reaction.

Hope this helps! :)

4 0

3 years ago

Match each of the three descriptions of a volume to the appropriate metric unit of volume

tankabanditka [31]

A.) 1.
b.) 3
c.) 2
I hope this helps.

8 0

3 years ago

On the window sill is a potted plant. The plant always seems to lean toward the window. Even though you turn its pot around ever

ICE Princess25 [194]

Answer:

because im trynna get these 5 points

Explanation:

mklnk.m

3 0

2 years ago

9. If 28.56 g of K2O is produced when 25.00 g K is reactedaccording to the following equation, what is the percent yieldof the r

Mumz [18]

Answer

b. 95%

Explanation

Given:

Mass of K₂O produced (actual yield) = 28.56 g

Mass of K that reacted = 25.00 g

Equation: 4K(s) + O₂(g) → 2K₂0(s)

What to find:

The percent yield of K₂O.

Step-by-step solution:

The first step is to calculate the theoretical yield of K₂O produced.

From the balanced equation, 4 mol K produced 2 mol K₂O

Molar mass of K₂O = 94.20 g/mol)

Molar mass of K = 39.10 g/mol)

This means 4 mol x 39.10 g/mol = 156.40 g K produced 2 mol x 94.20 g/mol = 188.40 g K₂O

So 25.00 g K will produce:

$\frac{25.00\text{ }g\text{ }K\times188.40\text{ }g\text{ }K₂O}{156.40\text{ }g\text{ }K}=30.1151\text{ }g\text{ }K₂O$

Actual yield of K₂O = 28.56 g

Theoretical yield of k₂O = 30.1151 g

The percent yield for the reaction can now be calculated using the formula below:

$\begin{gathered} Percent\text{ }yield=\frac{Actual\text{ }yield}{Theoretical\text{ }yield}\times100\% \\ \\ Percent\text{ }yield=\frac{28.56\text{ }g}{30.1151\text{ }g}\times100\% \\ \\ Percent\text{ }yield=0.9484\times100\% \\ \\ Percent\text{ }yield=94.84\%\approx95\% \end{gathered}$

Therefore, the percent yield for the reaction is 95%.

3 0

1 year ago

PLEASE HELP!!

REY [17]

The physical properties of water is that it is clear, it has no taste. No odour. It freezes at 0 degrees Celsius and boils at 100 degrees Celsius. The different stages of water is liquid, solid and gas. It is liquid at normal state. Ice when solid and steam when it is a gas state.

It is essential for human life because majority of the human body is made out of water. The water in the body allows certain parts and organs to function properly. Without water humans are most like to become I’ll and even dehydrate causing major injuries. It is also essential for the brain to function

3 0

2 years ago