How to find the percentage abundance of isotope

Answer:

B.Thermal insulation minimizes energy loses to the atmosphere.

Explanation:

It is important because it helps to stop hit from transferring from the calorimeter to the environment. This would help to have an accurate measurement of the heat that was used in the chemical process. The greatest cause of error that happens in calorimetry is when heat is lost to the environment. To reduce this, you insulate the calorimeter and add a cover.

Answer.

Universal indicator

Explanation.

Universal indicator has many different colour changes, from red for strongly acidic solutions to dark purple for strongly alkaline solutions. In the middle, neutral pH 7 is indicated by green.

The question is as follows: How many oxygen molecules are produced by the decomposition of 28.5 g of H2O2 (molecular mass = 34.0g / mol) according to the equation

2H2O2 (l) → 2H2O (l) + O2 (g)

Answer: There are [tex]2.52 \times 10^{23}[/tex] molecules are produced by the decomposition of 28.5 g of [tex]H_{2}O_{2}[/tex] according to the equation [tex]2H_{2}O(l) \rightarrow 2H_{2}O(l) + O_{2}(g)[/tex].

Explanation:

Given: Mass of [tex]H_{2}O_{2}[/tex] = 28.5 g

As moles is the mass of a substance divided by its molar mass. Hence, moles of [tex]H_{2}O_{2}[/tex] is calculated as follow.

[tex]Moles = \frac{mass}{molarmass}\\= \frac{28.5 g}{34.0 g/mol}\\= 0.838 mol[/tex]

According to the given equation, 2 moles of [tex]H_{2}O_{2}[/tex] gives 1 mole of [tex]O_{2}[/tex]. So, moles of [tex]O_{2}[/tex] produced by 0.838 moles of [tex]H_{2}O_{2}[/tex]  will be calculated as follows.

[tex]Moles of O_{2} = \frac{0.838 mol}{2}\\= 0.419 mol[/tex]

This means that moles of [tex]O_{2}[/tex] produced is 0.419 mol.

As per the mole concept, 1 mole of every substance has [tex]6.022 \times 10^{23}[/tex] molecules.

So, molecules of [tex]O_{2}[/tex] present in 0.419 mole are as follows.

[tex]0.419 \times 6.022 \times 10^{23}\\= 2.52 \times 10^{23}[/tex]

Thus, we can conclude that there are [tex]2.52 \times 10^{23}[/tex] molecules are produced by the decomposition of 28.5 g of [tex]H_{2}O_{2}[/tex] according to the equation [tex]2H_{2}O(l) \rightarrow 2H_{2}O(l) + O_{2}(g)[/tex].

Answer:

A = 65.46 u

Explanation:

Given that,

The composition of zinc is as follows :

Zn-64 = 48.63%

Zn-66 = 27.90%

Zn-67 = 4.10%

Zn-68 = 18.75%

Zn-70 = .62%

We need to find the  average atomic mass of the given element. It can be solved as follows :

[tex]A=\dfrac{48.63\times 64+27.90\times 66+4.1\times 67+18.75\times 68+0.62\times 70}{100}\\A=65.46\ u[/tex]

So, the average atomic mass of zinc is 65.46 u.

Explanation:

this is the reason why aluminium's boiling point is higher than that of sodium. sodium forms Na+ ions, therefore 1 electron is lost from each sodium atom, whereas aluminium forms Al3+ ions, so 3 electrons are lost for each Aluminum atom. The number of delocalised electrons therefore increases from sodium to aluminium, and charge density of the ions increases as the ionic charge increases and size decreases.

Answer:

He should ask an adult if they know what the solution is. if they dont, put it back and find a different cleaning solution to use

Answer: 1.224 moles of [tex]Na_3N[/tex] were used.

Explanation:

We are given:

Volume of nitrogen gas produced = 13.7 L

At STP conditions:

22.4 L of volume is occupied by 1 mole of a gas

Applying unitary method:

13.7 L of nitrogen gas will be occupied by = [tex]\frac{1mol}{22.4L}\times 13.7L=0.612mol[/tex]

For the given chemical reaction:

[tex]2Na_3N\rightarrow 6Na+N_2[/tex]

By Stoichiometry of the reaction:

1 mole of nitrogen gas is produced by 2 mole of [tex]Na_3N[/tex]

So, 0.612 moles of nitrogen gas will be produced from = [tex]\frac{2}{1}\times 0.612=1.224mol[/tex] of [tex]Na_3N[/tex]

Hence, 1.224 moles of [tex]Na_3N[/tex] were used.

Answer:

C. x⁴ + 6·x³ - 12·x  - 72

Explanation:

The given functions are;

[tex]f(x) =\sqrt{x^2 + 12 \cdot x + 36}[/tex]

g(x) = x³ -12

We have that [tex]f(x) =\sqrt{x^2 + 12 \cdot x + 36}[/tex] = [tex]f(x) =\sqrt{(x + 6)^2}[/tex] =  (x + 6)

Therefore;

f(x)·g(x) = [tex]\sqrt{x^2 + 12 \cdot x + 36}[/tex] × (x³ - 12) = (x + 6) × (x³ - 12)

(x + 6) × (x³ - 12) = x⁴ - 12·x + 6·x³ - 72 = x⁴ + 6·x³ - 12·x  - 72

∴ f(x)·g(x) = [tex]\sqrt{x^2 + 12 \cdot x + 36}[/tex] × (x³ - 12) = x⁴ + 6·x³ - 12·x  - 72

Too lazy to draw sorry lol.

#CarryOnLearning

I actually just looked it up via image search.

just copy by hand either of the flow charts.

if you can, use colors to fill. makes it more interesting to look at

and define a circle (or rather a few points on it) to draw it neatly. the defined points can later be transformed into the arrows.

Answer:

The mass of H2SO4 collected is 92.0g assuming the theoretical yield of H2SO4 is 100g

Explanation:

Assuming the theoretical yield of the sulfuric acid, H2SO4, is 100g.

To solve this question we must use the equation of percent yield:

Percent yield = Actual yield / Theoretical yield * 100

Where percent yield = 92.0%, actual yield is the mass of H2SO4 produced and theoretical yield is 100g, the mass we are assuming

Replacing:

92.0% = Actual yield / 100g * 100

92.0g = Actual Yield

Answer:

liquid  B

Explanation:

because B has a lower bp it needs less time and energy to turn into vapour and is collected into the condenser first

Answer:

Salts that produce acidic solutions are acid salts. Neutral salts are those salts that are neither acidic nor basic. Zwitterions contain an anionic and a cationic centre in the same molecule, but are not considered to be salts. Examples of zwitterions include amino acids, many metabolites, peptides, and proteins.

Explanation:

Answer:

Molecular mass, M = 58.20 g/mol.

Explanation:

Given the following data;

Conversion:

760 mmHg = 1 atm

770 mmHg = 770/760 = 1.0131 atm

Temperature = 25°C = 273 + 25 = 298 K

To find the molecular mass, we would use the ideal gas law equation (density version);

PM = dRT

Where;

Making M the subject of formula, we have;

[tex] M = \frac {dRT}{P} [/tex]

Substituting into the formula, we have;

[tex] M = \frac {2.41 * 0.0821 * 298}{1.0131} [/tex]

[tex] M = \frac {58.9626}{1.0131} [/tex]

Molecular mass, M = 58.20 g/mol.

Answer:

B

Explanation:

because B has a lower bp it needs less time and energy to turn into vapour and is collected into the condenser first

Answer:

reaction

Explanation:

A reaction is defined as a process where the chemical transformation takes place from one form to some other form. Here, two different chemical substances are reacted together to form some other completely different product.

A hydrogenation process is a chemical process where between the molecular hydrogen and some another element or a compound. This process is usually carried out in the presence of catalyst mainly nickel, platinum or palladium.

Thus, in hydrogenation of a double bond, the catalyst is used to speed up the reaction. The first step in this process is adsorption process, the second step is the diffusion process, the third step is the reaction process and the last step is the desorption process.

Answer:

total displacement \time

Explanation:

Answer:

Al

Explanation:

It has 3.

Answer:

option B is the correct answer

Answer:

[tex]\boxed {\boxed {\sf 55.76756 \ amu}}[/tex]

Explanation:

The average atomic mass is the sum of the product of the given masses and their abundances. We have to complete two steps for each isotope, then add all the products together.

Fe-54

Convert the percent abundance to a decimal by dividing by 100.

Multiply the abundance as a decimal by the mass number. This is the number after the element in the isotope symbol (54 amu).

Fe-56

Convert the percent to a decimal.

Multiply the decimal by the mass number (56 amu).

Fe-58

Convert the percent to a decimal.

Multiply by the mass number (58 amu).

Average Atomic Mass

Add all the products together to find the average atomic mass.

The average atomic mass given the percent abundance is 55.7656 atomic mass units.

Explanation:

Oceans can influence weather and climate. For example, cities located near large water bodies like oceans tend not to have extreme climates

Answer:

D Period 1, Group 18

Explanation:

it's helium

it's top right corner of the periodic table

Answer:

Density of the solid=[tex]2.78 g/cm^3[/tex]

Explanation:

We are given that

Mass of sample of metal=4.369 g

Volume in the flask, V=126.4 ml

Mass of water, flask, and metal=268.5 g

Mass of flask=139.3 g

Density of water=1.000 g/mL

We have to find the density of the solid.

Mass of water=268.5-4.369-139.3=124.831 g

Volume of water=[tex]\frac{Mass\;of\;water}{density\;of\;water}[/tex]

Volume of water=[tex]\frac{124.831}{1}=124.831 mL[/tex]

Volume of solid=126.4 ml-124.831 mL

=1.569mL

Now,

Density of the solid=[tex]\frac{mass\;of\;solid}{volume\;of\;solid}[/tex]

=[tex]\frac{4.369}{1.569}[/tex]

[tex]=2.78g/mL[/tex]

1mL=1 cubic cm

Therefore,

Density of the solid=[tex]2.78 g/cm^3[/tex]

Answer:

Option A. ⁰₋₁β

Explanation:

Let the unknown be ʸₓA

Thus, the equation given becomes:

⁹⁸₄₃Tc —> ⁹⁸₄₄Ru + ʸₓA

Next, we shall determine the value of x, y and A in order to obtain the answer to the question. This can be obtained as follow:

43 = 44 + x

Collect like terms

43 – 44 =

–1 = x

x = –1

98 = 98 + y

Collect like terms

98 – 98 = y

0 = y

y = 0

ʸₓA => ⁰₋₁A => ⁰₋₁β

Thus, the complete equation is

⁹⁸₄₃Tc —> ⁹⁸₄₄Ru + ⁰₋₁β

The missing item is ⁰₋₁β

Answer:

True

Explanation:

An atom would carry more protons if positively charged, an equal amount of both protons and electrons if neutral, and more electrons if charged negative.

Answer:

CH3—CH2—O—CH2—CH3 is the compound of glycol.

Answer:

HOH2C―CH2―CH2―CH2OH is glycol

Explanation:

Answer:

resend again that question dear

Answer:

Explanation:

Volume of one mole of a gas = 22.4 litre.

No of molecules in one mole of gas = 6.02 x 10²³ .

Volume of one molecule = 4/3 π R³

= 4/3 x 3.14 x ( 167 x 10⁻¹² m )³

= 19.5 x 10⁶ x 10⁻³⁶ m³

=19.5 x 10⁻³⁰ m³

= 19.5 x 10⁻³⁰ x 10³ litre .

=  19.5 x 10⁻²⁷ litre .

So volume occupied by molecules in one mole of gas

= 19.5 x 10⁻²⁷ x 6.02 x 10²³  litre

117.4 x 10⁻⁴ litre

= .01174 litre.

Excluded volume

= ( 22.4 -  .01174  ) litre .

= 22.388 litre.

Answer:

2117.02 litres

Explanation:

Using the ideal gas equation as follows;

PV = nRT

Where:

P = pressure of the gas (atm)

V = volume of the gas (L)

n = number of moles (mol)

R = gas law constant (Latm/molK)

T = temperature (K)

According to the information given in this question,

P = 0.12 atm

V = ?

n = 9.7moles

T = 46°C = 46 + 273 = 319K

R = 0.0821 Latm/molK

Using PV = nRT

0.12 × V = 9.7 × 0.0821 × 319

0.12V = 254.04

V = 254.04 ÷ 0.12

V = 2117.02 litres