Help me with please !!!

Which is one way that scientist communicate the results of an experiment

Slav-nsk [51]

Draw conclusions,............

3 0

4 years ago

A 0.500-g sample of chromium metal reacted with sulfur powder to give 0.963 g of product. Calculate the empirical formula of the

IgorC [24]

Answer: The empirical formula for the given compound is $Cr_2S_3$

Explanation : Given,

Mass of product = 0.963 g

Mass of Cr = 0.500 g

Mass of S = 0.963 g - 0.500 g = 0.463 g

To formulate the empirical formula, we need to follow some steps:

Step 1: Converting the given masses into moles.

Moles of Cr = $\frac{\text{Given mass of Cr}}{\text{Molar mass of Cr}}=\frac{0.500g}{52g/mole}=0.00962moles$

Moles of S = $\frac{\text{Given mass of S}}{\text{Molar mass of S}}=\frac{0.463g}{32g/mole}=0.0145moles$

Step 2: Calculating the mole ratio of the given elements.

For the mole ratio, we divide each value of the moles by the smallest number of moles calculated which is 0.00962 moles.

For Cr = $\frac{0.00962}{0.00962}=1$

For S = $\frac{0.0145}{0.00962}=1.5$

To make in a whole number we are multiplying the ratio by 2, we get:

The ratio of Cr : S = 1 : 1.5

The ratio of Cr : S = 2 : 3

Step 3: Taking the mole ratio as their subscripts.

The ratio of Cr : S = 2 : 3

Hence, the empirical formula for the given compound is $Cr_2S_3$

8 0

4 years ago

consider the reaction between acetylene C2H2 and oxygen in a welding torch 2C2H2 + 5O2 = 4CO2 + 2H2O of 5.4 moles of acetylene r

Eddi Din [679]

Answer:

C. 4.8*10² g.

Explanation:

5 0

3 years ago

Choose the correct total number of electron domains (bonding and nonbonding) about a central atom if the angle(s) between the el

slamgirl [31]

Answer:

The central atom has 3 electron domains.

Explanation:

According to the Valence Shell electron pair repulsion theory (VSEPR) put forward by Gillespie and Nyholm in 1957, the shape of a molecule is determined by repulsion between all the electron pairs (electron domains) present in the valence shell.

The electron pairs or electron domains are known to position themselves as far apart in space as possible in order to minimize repulsions.

Hence, when the central atom of a molecule contains three electron domains, they are positioned at an angle of 120° from each other to minimize repulsions. Hence the answer.

5 0

4 years ago

A chemist must dilute 47.2 mL of 150. mM aqueous sodium nitrate solution until the concentration falls to . He'll do this by add

erma4kov [3.2K]

Answer:

0.295 L

Explanation:

It seems your question lacks the final concentration value. But an internet search tells me this might be the complete question:

" A chemist must dilute 47.2 mL of 150. mM aqueous sodium nitrate solution until the concentration falls to 24.0 mM. He'll do this by adding distilled water to the solution until it reaches a certain final volume. Calculate this final volume, in liters. Be sure your answer has the correct number of significant digits. "

Keep in mind that if your value is different, the answer will be different as well. However the methodology will remain the same.

To solve this problem we can<u> use the formula</u> C₁V₁=C₂V₂

Where the subscript 1 refers to the concentrated solution and the subscript 2 to the diluted one.

47.2 mL * 150 mM = 24.0 mM * V₂

V₂ = 295 mL

And <u>converting into L </u>becomes:

295 mL * $\frac{1 L}{1000mL}$ = 0.295 L

6 0

4 years ago