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3 years ago

25) Which of the following would exert the most pressure on the ground? 3 points

Chemistry

2 answers:

Zarrin [17]3 years ago

8 0

Answer:

a women standing in high heels

Explanation:

ZanzabumX [31]3 years ago

4 0

Answer:

A woman standing in high heels

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Bismuth oxide reacts with carbon to form bismuth metal: Bi2O3(s) + 3C(s) → 2Bi(s) + 3CO(g) When 775 g of Bi2O3 reacts with exces

goldfiish [28.3K]

Answer:

(a) 3.33 mol Bi

(b) 140. g CO

Explanation:

Step 1: Convert 775g to moles

Bi Molar Mass - 208.98 g/mol × 2 = 417.98 g/mol

O Molar Mass - 16.00 g/mol × 3 = 48.00 g/mol

775g Bi₂O₃ ÷ 465.98 g/mol = 1.66316 mol Bi₂O₃

Step 2: Find the conversion from Bi₂O₃ to Bi

1 mole of Bi₂O₃ equals 2 moles of Bi

Step 3: Use Dimensional Analysis

1.66316 mol · $\frac{2 \hspace{2} mol \hspace{2} Bi}{1 \hspace{2} mol \hspace{2} Bi_2O_3}$ = 3.32632 mol Bi

3.32632 mol Bi ≈ 3.33 mol Bi (3 significant figures)

Step 4: Find the conversion from Bi₂O₃ to CO

1 mole of Bi₂O₃ equals 3 moles of CO

Step 5: Use Dimensional Analysis

1.66316 mol · $\frac{3 \hspace{2} mol \hspace{2} CO}{1 \hspace{2} mol \hspace{2} Bi_2O_3}$ = 4.98948 mol CO

Step 6: Find molar mass of CO and convert moles to grams

C - 12.01 g/mol

O - 16.00 g/mol

4.98948 mol CO · 28.01 g/mol = 139.775 g CO

139.775 g CO ≈ 140. g CO (3 significant figures)

6 0

3 years ago

Is CaO binary or polyatomic?

Annette [7]

Answer:

CaO is a binary compound.

3 0

3 years ago

Read 2 more answers

A 0.2500 g sample of an alloy reacts with to form hydrogen gas: 2Al(s) + 6H+(aq) 2Al3+(aq) + 3H2(g) Zn(s) + 2H+(aq) Zn2+(aq) + H

fenix001 [56]

Answer: The mass percent of zinc in the alloy is 78.68 %

Explanation:

We are given:

Mass of sample of alloy = 0.2500 g

Let the mass of aluminium be 'x' grams and mass of zinc will be (0.2500 - x) g

To calculate the amount of hydrogen gas produced, we use the equation given by ideal gas which follows:

$PV=nRT$

where,

P = pressure of the gas = 755 mmHg

V = Volume of the gas = 0.147 L

T = Temperature of the gas = $25^oC=[25+273]K=298K$

R = Gas constant = $62.3637\text{ L.mmHg }mol^{-1}K^{-1}$

n = number of moles of hydrogen gas = ?

Putting values in above equation, we get:

$755mmHg\times 0.147L=n\times 62.3637\text{ L.mmHg }mol^{-1}K^{-1}\times 298K\\\\n=\frac{755\times 0.147}{62.3637\times 298}=0.00597mol$

To calculate the number of moles, we use the equation:

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$ .....(1)

For Aluminium:

Molar mass of aluminium = 27 g/mol

Putting values in equation 1, we get:

$\text{Moles of aluminium}=\frac{x}{27}mol$

The chemical equation follows:

$2Al(s)+6H^+(aq.)\rightarrow 2Al^{3+}(aq.)+3H_2(g)$

By Stoichiometry of the reaction:

2 moles of aluminium produces 3 moles of hydrogen gas

So, $\frac{x}{27}$ moles of aluminium will produce = $\frac{3}{2}\times \frac{x}{27}=\frac{3x}{54}mol$ of hydrogen gas

For Zinc:

Molar mass of zinc = 65.4 g/mol

Putting values in equation 1, we get:

$\text{Moles of zinc}=\frac{(0.25-x)}{65.4}mol$

The chemical equation follows:

$Zn(s)+2H^+(aq.)\rightarrow Zn^{2+}(aq.)+H_2(g)$

By Stoichiometry of the reaction:

1 mole of zinc produces 1 moles of hydrogen gas

So, $\frac{(0.25-x)}{65.4}$ moles of zinc will produce = $\frac{1}{1}\times \frac{(0.25-x)}{65.4}=\frac{(0.25-x)}{65.4}mol$ of hydrogen gas

Equating the moles of hydrogen gas:

$\Rightarrow 0.00597=\frac{3x}{54}+\frac{(0.25-x)}{65.4}\\\\x=0.0533g$

To calculate the mass percentage of zinc in alloy, we use the equation:

$\text{Mass percent of zinc}=\frac{\text{Mass of zinc}}{\text{Mass of alloy}}\times 100$

Mass of zinc = (0.2500 - x) = [0.2500 - 0.0533] = 0.1967 g

Mass of alloy = 0.2500 g

Putting values in above equation, we get:

$\text{Mass percent of zinc in alloy}=\frac{0.1967g}{0.2500g}\times 100=78.68\%$

Hence, the mass percent of zinc in the alloy is 78.68 %

8 0

4 years ago

What is a forensic paleontologist? dum it down for me

raketka [301]

Answer:

Simple Definition: A Tool for “Intelligence” and Investigation

Explanation:

Intelligence is the ability to acquire and apply knowledge and skills while investigation is the action of investigating something or someone; formal or systematic examination or research.

4 0

2 years ago

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A metal ion Mⁿ⁺ has a single electron. The highest energy line in its emission spectrum occurs at a frequency of 2.961 x 10¹⁶ Hz

Whitepunk [10]

Answer:

z≅3

Atomic number is 3, So ion is Lithium ion ( $Li^+$ )

Explanation:

First of all

v=f*λ

In our case v=c

c=f*λ

λ=c/f

where:

c is the speed of light

f is the frequency

$\lambda=\frac{3*10^8}{2.961*10^{16}}\\ \lambda=1.01317*10^{-8} m$

Using Rydberg's Formula:

$\frac{1}{\lambda}=R*z^2*(\frac{1}{n_1^2}-\frac{1}{n_2^2})$

Where:

R is Rydberg constant= $1.097*10^7$

z is atomic Number

For highest Energy:

n_1=1

n_2=∞

$\frac{1}{1.01317*10^{-8}}=1.097*10^{7}*z^2*(\frac{1}{1^2}-\frac{1}{\inf})\\z^2=8.99\\z=2.99$

z≅3

Atomic number is 3, So ion is Lithium ion ( $Li^+$ )

3 0

4 years ago