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3 years ago

A sample of silver has a mass of 21 grams

Chemistry

2 answers:

ad-work [718]3 years ago

8 0

Answer:

$density \: of \: the \: silver = \frac{mass}{volume} = \frac{21}{2} \\ = 10.5 \: gram {(cm)}^{ - 3}$

<h2>10.5 gram(cm)^-3 is the right answer.</h2>

mylen [45]3 years ago

6 0

Explanation:

recall that density is equal to mass/volume :21÷2= 10.5g/cm3

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Which statement is NOT true of molecular orbitals: Select one

trapecia [35]

Answer:

A: Antibonding molecular orbitals are higher in energy than all of the bonding molecular orbitals.

Explanation:

Molecular orbital theory describes <u>covalent bonds in terms of molecular orbitals</u>, which result from interaction of the atomic orbitals of the bonding atoms and are associated with the entire molecule.

A bonding molecular orbital has lower energy and greater stability than the atomic orbitals from which it was formed. An antibonding molecular orbital has higher energy and lower stability than the atomic orbitals from which it was formed.

Electrons in the antibonding molecular orbital have higher energy (and less stability) than they would have in the isolated atoms. On the other hand, electrons in the bonding molecular orbital have less energy (and hence greater stability) than they would have in the isolated atoms.

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3 years ago

The cost, C C, of producing x x Totally Cool Coolers is modeled by the equation C = 0.005 x 2 − 0.25 x + 12 C=0.005x2-0.25x+12 H

neonofarm [45]

Answer:

25 coolers are need to be produce and sell in order to minimize the cost.

Explanation:

$C = 0.005x^2-0.25x+12$ ..[1]

Differentiating the given expression with respect to dx.

$\frac{dC}{dx}=\frac{d(0.005x^2-0.25x+12)}{dx}$

$\frac{dC}{dx}=0.01x-0.25+0$

Putting , $\frac{dC}{dx}=0$

$0=0.01x-0.25+0$

$0.01x=0.25$

x = 25

Taking second derivative of expression [1]

$\frac{d^2C}{dx^2}=\frac{d(0.01x-0.25)}{dx}=0.01$

$\frac{d^2C}{dx^2}>0$ (minima)

25 coolers are need to be produce and sell in order to minimize the cost.

3 0

3 years ago

if 14.0 g of aluminium reacts with excess sulfuric acid to produce 75.26 g of aluminium sulfate, what is the percent yield?

vlada-n [284]

Taking into account definition of percent yield, the percent yield for the reaction is 84.88%.

<h3>Reaction stoichiometry</h3>

In first place, the balanced reaction is:

2 Al + 3 H₂SO₄ → Al₂(SO₄)₃ + 3 H₂

By reaction stoichiometry (that is, the relationship between the amount of reagents and products in a chemical reaction), the following amounts of moles of each compound participate in the reaction:

Al: 2 moles
H₂SO₄: 3 moles
Al₂(SO₄)₃. 1 mole
H₂: 3 moles

The molar mass of the compounds is:

Al: 27 g/mole
H₂SO₄: 98 g/mole
Al₂(SO₄)₃: 342 g/mole
H₂: 2 g/mole

Then, by reaction stoichiometry, the following mass quantities of each compound participate in the reaction:

Al: 2 moles ×27 g/mole= 54 grams
H₂SO₄: 3 moles ×98 g/mole= 294 grams
Al₂(SO₄)₃: 1 mole ×342 g/mole= 342 grams
H₂: 3 moles ×2 g/mole= 6 grams

<h3>Mass of aluminium sulfate formed</h3>

The following rule of three can be applied: if by reaction stoichiometry 54 grams of aluminium form 342 grams of aluminium sulfate, 14 grams of aluminium form how much mass of aluminium sulfate?

$mass of aluminium sulfate=\frac{14 grams of aluminium x342 grams of aluminium sulfate}{54 grams of aluminium}$

<u><em>mass of aluminium sulfate= 88.67 grams</em></u>

Then, 88.67 grams of aluminium sulfate can be produced if 14.0 g of aluminium reacts with excess sulfuric acid.

<h3>Percent yield</h3>

The percent yield is the ratio of the actual return to the theoretical return expressed as a percentage.

The percent yield is calculated as the experimental yield divided by the theoretical yield multiplied by 100%:

$percent yield=\frac{actual yield}{theorical yield} x100$

where the theoretical yield is the amount of product acquired through the complete conversion of all reagents in the final product, that is, it is the maximum amount of product that could be formed from the given amounts of reagents.

<h3>Percent yield for the reaction in this case</h3>

In this case, you know:

actual yield= 75.26 grams
theorical yield= 88.67 grams

Replacing in the definition of percent yields:

$percent yield=\frac{75.26 grams}{88.67 grams} x100$

Solving:

<u><em>percent yield= 84.88%</em></u>

Finally, the percent yield for the reaction is 84.88%.

Learn more about

the reaction stoichiometry:

brainly.com/question/24741074

brainly.com/question/24653699

percent yield:

brainly.com/question/14408642

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2 years ago

Balance the following reaction. A coefficient of \"1\" is understood. Choose option \"blank\" for the correct answer if the coef

g100num [7]

Conservation of mass is the underlying principle of balancing equation. When we balance equation, this means that we acknowledge that before and after the chemical reaction, the elements are conserved. To balance the chemical equation, we add coefficients before each reactant and product. Here are the following answers:

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<span>2Al
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3Zn
2AlCl3
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6H2O</span>

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3 years ago

DNA contains which sugar molecule?

pishuonlain [190]

dna contains phosphate

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3 years ago