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3 years ago

How many moles of aluminum do 4.60x10^24 aluminum represent? Express your answer using three significant figures.

Chemistry

1 answer:

stiks02 [169]3 years ago

6 0

Answer:

7.64 Moles

Explanation:

As we know one mole of any substance contains 6.022 × 10²³ particles (atoms, ions, molecules or formula units). This number is also called as Avogadro's Number.

The relation between Moles, Number of Particles and Avogadro's Number is given as,

Number of Moles = Number of Particles ÷ 6.022 × 10²³

Putting values,

Number of Moles = 4.60 × 10²⁴ Particles ÷ 6.022 × 10²³

Number of Moles = 7.64 Moles

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What are the formal charges on the sulfur (s), carbon (c), and nitrogen (n) atoms, respectively, in the resonance structure that

sergiy2304 [10]

Answer:

Sulfur: -1

Carbon: 0

Nitrogen: 0

Explanation:

The thiocyanate ion SCN- can have only two resonance structures, which are:

S - C ≡ N <--------> S = C = N

In the first structure, we have one single bond and one triple bond, in this case, the negative charge is located in the sulfur. This is because Sulfur have 6 electrons and those electrons are present in the atom, (see picture below), and counting the electron that is sharing with the Carbon, the total electrons that sulfur has is 7 (It has one more than usual). Carbon and nitrogen are already stable with 0 of formal charge, because carbon can only have 4 electrons which 1 is sharing with sulfur and the other 3 with the nitrogen, and nitrogen have 5 electrons, three sharing with carbon and the other two kept it for itself.

In the second structure, the negative charge of the sulfur is transfered to the nitrogen, meaning that it has 6 electrons the nitrogen (formal charge -1) and carbon and sulfur with 4 and 6 electrons respectively.

Between these two structures, the most stable is the first one basically because Sulfur is a better nucleophile than the Nitrogen, and can form stronger hydrogen bond in acid, giving more stable structure.

7 0

3 years ago

Read 2 more answers

Using the average initial pH of your acetic acid solutions (2.96), and the average molarity of those solutions(.0602), calculate

Orlov [11]

Answer : The value of Ka for acetic acid is, $2.03\times 10^{-5}$

Explanation :

The chemical formula of acetic acid is, $CH_3COOH$ .

The chemical equilibrium reaction will be:

$CH_3COOH\rightleftharpoons CH_3COO^-+H^+$

Given:

pH = 2.96

First we have to calculate the concentration of hydrogen ion.

$pH=-\log [H^+]$

$2.96=-\log [H^+]$

$[H^+]=1.096\times 10^{-3}M$

That means,

$[H^+]=[CH_3COO^-]=1.096\times 10^{-3}M$

$[CH_3COOH]=0.0602-(1.096\times 10^{-3})=0.0591M$

The expression for reaction is:

$K_a=\frac{[CH_3COO^-][H^+]}{[CH_3COOH]}$

$K_a=\frac{(1.096\times 10^{-3})\times (1.096\times 10^{-3})}{0.0591}$

$K_a=2.03\times 10^{-5}$

Thus, the value of Ka for acetic acid is, $2.03\times 10^{-5}$

3 0

3 years ago

Which material property is most directly related to the x-axis value at the x-intercept of the interatomic force versus distance

Brrunno [24]

Answer:

Explanation:

The mechanical properties of a material affect how it behaves as it is loaded. The elastic modulus of the material affects how much it deflects under a load, and the strength of the material determines the stresses that it can withstand before it fails

3 0

2 years ago

You take three compounds consisting of two elements and decompose them. To determine the relative masses of X, Y, and Z, you col

miss Akunina [59]

Answer:

a) LAW OF MULTIPLE PROPORTIONS

b) 0.095g, 0.71g, 0.285g respectively

c) X2Y, YZ15, X6Y

d) hence mass of compound X = 21 x 0.045 = 0.95g

mass of compound Y = 21 x 0.955 = 20.05g

Explanation:

a) The assumptions made in solving this questions is the application of the LAW OF MULTIPLE PROPORTIONS. The Law of multiple proportions states that if two elements A and B combine together to form more than one compound, then the several masses of A which chemically combine with a fixed mass of B is in a simple ratio.

for example, copper forms two oxides ; copper(I) oxide (CuO) and copper(ii) oxide(Cu2O), it is possible for the two samples of the oxides to be reduced to Cu by reacting with Hydrogen gas. as such, certain masses of oxygen combine separately with a fixed mass of Cu. then the ratios of Cu are then determined.

b) To calculate the relative masses, we take note of the three compounds given, they all have some amount of Y in them, hence we can use Y as our relative mass, this implies that the relative mass of Y = 1g

mass of X = 0.4g

mass of Y = 4.2g

amount of X in 1g of Y = 0.4 x 1 /4.2

= 0.095g

for compound 2;

mass of Y = 1.4g

mass of Z = 1.0g

amount of Z in 1g of Y =1.0 x 1 /1.4

= 0.71g

for compound 3;

mass of X = 2.0g

mass of Y = 7.0g

amount of X in 1g of Y = 1 x 2/7

= 0.285g

c) Applying the law of multiple proportions; since elements X and Z combine with a fixed mass of Y, they must bear a simple ratio;

compound 1/compound 3 = 0.095/0.285

= 1/3

compound 1/compound 2 = 0.095/0.71

= 2/15

compound 2/ compound 3 = 0.71/0.285

= 5/2

formular for compound 1 = X2Y

formula for compound 2 = YZ15

formular for compound 3 = X6Y

d) from the formular X2Y, we can get the amount of each product in XY using the ratios

%of compound XY in X = mass of compound X / total Mass

= 0.2/4.4 = 4.5%

as such in a 21g of compound XY, %of compound Y = 1 - %of compound X = 95.5%

hence mass of compound X = 21 x 0.045 = 0.95g

mass of compound Y = 21 x 0.955 = 20.05g

5 0

3 years ago

How can you tell whether a fat contains primarily saturated or unsaturated fatty acids?

Romashka-Z-Leto [24]

In terms of physically observing it, if the substance is a lions based substance, like oil or margarine, depending on the state, this will inform how well the hydrocarbons can pack together well or not, or will there be bends in the ring preventing the molecules from packing well.

Liquids are unsaturated
Solids are saturated.

3 0

3 years ago