How do you calculate annual layers of snow from the past?

HELP!!!!!What is the molar mass of a gas which has a density of .249 g/L at 20.0 degrees Celsius and a pressure of .95 atm?

fgiga [73]

Answer:

6.31g/mol

Explanation:

Using the ideal gas equation;

PV = nRT

Where;

P = pressure (atm)

V = volume (L)

n = number of moles (mol)

R = gas law constant (0.0821 Latm/molK)

T = temperature (K)

Mole (n) = mass (m)/molar mass (Mm)

* Mm = m/n

Also, density (p) = mass (m) ÷ volume (V)

PV = nRT

Since n = M/Mm

PV = M/Mm. RT

PV × Mm = m × RT

Divide both sides by V

P × Mm = m/V × RT

Since p = m/V

P × Mm = p × RT

Mm = p × RT/P

Mm = 0.249 × 0.0821 × 293/0.95

Mm = 5.989 ÷ 0.95

Mm = 6.31g/mol

7 0

3 years ago

Select the correct answer

Assoli18 [71]

Answer:

B. an element

Explanation:

An atom is smallest indivisible particle that takes part in a chemical reaction. Different atoms due to the number of their protons called atomic number gives an element. Every element is a singular atom on it's own. Combination of atoms leads to the formation of molecules and compounds.

When compounds mix together without an actual chemical change, a mixture forms.

Elements are distinct substances that cannot be split up into simpler substances. They are usually made up of only one kind of atom.

4 0

3 years ago

Given the following chemical equation, if 50.1 grams of silicon dioxide is heated with excess carbon and 32.3 grams of silicon c

aivan3 [116]

Answer:

97%.

Explanation:

We'll begin by writing the balanced equation for the reaction. This is given below:

SiO2 (s) + 3C (s) —> SiC(s) + 2CO(g)

Next, we shall determine the mass of SO2 that reacted and the mass of SiC produced from the balanced equation. This is illustrated below:

Molar mass of SiO2 = 28 + (16x2) = 60 g/mol

Mass of SO2 from the balanced equation = 1 x 60 = 60 g

Molar mass of SiC = 28 + 12 = 40 g/mol

Mass of SiC from the balanced equation = 1 x 40 = 40 g.

From the balanced equation above,

60 g of SiO2 reacted to produce 40 g of SiC.

Next, we shall determine the theoretical yield of SiC. This can be obtained as follow:

From the balanced equation above,

60 g of SiO2 reacted to produce 40 g of SiC.

Therefore, 50.1 g of SiO2 will react to produce = (50.1 x 40)/60 = 33.4 g of SiC.

Therefore, the theoretical yield of SiC is 33.4 g

Finally, we shall determine the percentage yield of SiC as follow:

Actual yield of SiC = 32.3 g

Theoretical yield of SiC = 33.4 g

Percentage yield =?

Percentage yield = Actual yield /Theoretical yield x 100

Percentage yield = 32.3/33.4 x 100

Percentage yield = 96.7 ≈ 97%

Therefore, the percentage yield of the reaction is 97%.

3 0

3 years ago

For each value of the principal quantum number n, what are the possible values of the electron spin quantum number?

Ede4ka [16]

Answer:

The values for spin quantum number +1/2 and - 1/2

Explanation:

Principal quantum number denoted by (n) is used to describe the shell or orbits that electrons are found. Principal quantum number can assume a value of n= 1,2, 3, 4,5............ which indicates K, L, M, N, O shell respectively.

To know the maximum number of electrons in each shell, the formula (2n²) can be used. The letter 'n' denotes the values of principal quantum number 1,2,3,4

For example

n=1 (K shell) has maximum number of 2 electrons
n=2 (L shell) has the maximum number of 8 electrons
n=3 (M shell) has the maximum number of 18 electrons
n=4 (N shell) has the maximum number of 32 electrons

All the electron in each shell will have a spin quantum number of +1/2 and - 1/2. One electron in each degenerate orbital will spin up (+1/2) while the other electron will spin down (-1/2).

7 0

3 years ago

Silver sulfadiazine burn-treating cream creates a barrier against bacterial invasion and releases antimicrobial agents directly

trapecia [35]

Answer : The mass of silver sulfadiazine produced can be, 71.35 grams.

Solution : Given,

Mass of $Ag_2O$ = 25.0 g

Mass of $C_{10}H_{10}N_4SO_2$ = 50.0 g

Molar mass of $Ag_2O$ = 231.7 g/mole

Molar mass of $C_{10}H_{10}N_4SO_2$ = 250.3 g/mole

Molar mass of $AgC_{10}H_{9}N_4SO_2$ = 357.1 g/mole

First we have to calculate the moles of $Ag_2O$ and $C_{10}H_{10}N_4SO_2$ .

$\text{ Moles of }Ag_2O=\frac{\text{ Mass of }Ag_2O}{\text{ Molar mass of }Ag_2O}=\frac{25.0g}{231.7g/mole}=0.1079moles$

$\text{ Moles of }C_{10}H_{10}N_4SO_2=\frac{\text{ Mass of }C_{10}H_{10}N_4SO_2}{\text{ Molar mass of }C_{10}H_{10}N_4SO_2}=\frac{50.0g}{250.3g/mole}=0.1998moles$

Now we have to calculate the limiting and excess reagent.

The balanced chemical reaction is,

$Ag_2O(s)+2C_{10}H_{10}N_4SO_2(s)\rightarrow 2AgC_{10}H_9N_4SO_2(s)+H_2O(l)$

From the balanced reaction we conclude that

As, 2 mole of $C_{10}H_{10}N_4SO_2$ react with 1 mole of $Ag_2O$

So, 0.1998 moles of $C_{10}H_{10}N_4SO_2$ react with $\frac{0.1998}{2}=0.0999$ moles of $Ag_2O$

From this we conclude that, $Ag_2O$ is an excess reagent because the given moles are greater than the required moles and $C_{10}H_{10}N_4SO_2$ is a limiting reagent and it limits the formation of product.

Now we have to calculate the moles of $AgC_{10}H_9N_4SO_2$

From the reaction, we conclude that

As, 2 mole of $C_{10}H_{10}N_4SO_2$ react with 2 mole of $AgC_{10}H_9N_4SO_2$

So, 0.1998 mole of $C_{10}H_{10}N_4SO_2$ react with 0.1998 mole of $AgC_{10}H_9N_4SO_2$

Now we have to calculate the mass of $AgC_{10}H_9N_4SO_2$

$\text{ Mass of }AgC_{10}H_9N_4SO_2=\text{ Moles of }AgC_{10}H_9N_4SO_2\times \text{ Molar mass of }AgC_{10}H_9N_4SO_2$

$\text{ Mass of }AgC_{10}H_9N_4SO_2=(0.1998moles)\times (357.1g/mole)=71.35g$

Therefore, the mass of silver sulfadiazine produced can be, 71.35 grams.

8 0

3 years ago