Help me answer this question pls

What is the mass of 2.90 ×1022 formula units of NaOH (Molar mass = 40.0 g/mol)?

enyata [817]

<h3>Solution:</h3>

$\text{mass of NaOH = 2.90 × 10²² NaOH formula units} × \frac{\text{1 mol NaOH}}{\text{6.022 × 10²³ NaOH formula units}} × \frac{\text{40.0 g NaOH}}{\text{1 mol NaOH}}$

$\boxed{\text{mass of NaOH = 1.926 g}}$

5 0

3 years ago

Read 2 more answers

(Atomic masses used are C = 12.0 g mol–1, O = 16.0 g mol–1, H = 1.01 g mol–1, Cu = 63.5 g mol–1,)

alex41 [277]

Question 1

The formula mass of methanol is $12.0+3(1.01)+16.0+1.01=32.04$ g/mol.

Therefore, in 5.0 grams of methanol, there are $5.0/32.04=\boxed{0.16}$ moles.

Question 2

The formula mass of copper(II) carbonate is $63.5+12.0+3(16.0)=123.5$ g/mol.

This means that in 9.0 grams of copper(II) carbonate, there are $9.0/123.5=0.072874493927126$ moles.

Using Avogradro's number, there are $(0.072874493927126)(6.022 \times 10^{23})=\boxed{4.4 \times 10^{22}}$ molecules.

Question 3

The formula mass of cyclohexane is $12.0(6)+1.01(12)=84.12$ g/mol.

So, 3.0 grams of cyclohexane is the same as $3.0/84.12=\boxed{0.036}$ moles.

Question 4

The formula mass of benzene is $12.0(6)+1.01(6)=78.06$ g/mol.

This means that 4.00 moles of benzene has a mass of $(78.06)(4.00)=\boxed{312}$ grams.

Question 5

1000 atoms of calcium is the same as $\frac{1.000}{6.022 \times 10^{23}}$ moles.

This is equal to $\frac{1000}{6.022 \times 10^{23}} \cdot 40.078=\boxed{6.7 \times 10^{-20}}$ grams.

6 0

11 months ago

What is the force in the stretched rope that is attached to a bucket being pulled out of a well?

bezimeni [28]

The force of gravity acts upon all objects; the Earth and the object attract. There are no springs touching the object; thus, there is no spring force. A taut rope is attached to the bucket; this is the cause of the tension force.

3 0

2 years ago

I need help with this

masha68 [24]

Answer is —-7373/63)3

6 0

2 years ago

Classify unopened root beer as an element, a compound, a homogeneous mixture, or a heterogeneous mixture

maxonik [38]

The different state of material based on its ingredients are-

1. Compound: The compound is in which there are more than one molecule in which chemical bond is there.

2. Mixture: It is basically presence of two or more compounds in which there is no chemical bonds.

The mixture may be of two types (i) homogeneous and (ii) Heterogeneous. In the homogeneous mixture there is uniformity of the mixed compound (like air in water) and some chemical process is needed to separate the compounds. Whereas heterogeneous mixtures (like chalk in water) are easily separable by any physical process.

In the root beer which is a soft drink which is obtained in different flavor sometime with caffeine and without caffeine. The unopened bottle of root beer is homogeneous mixture.

4 0

3 years ago