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What is the mass of 3.50 moles of Ba(NO2)2?

Fofino [41]

Answer:

802.69 g

Explanation:

The molar mass of Barium nitrite is 229.34 g/mol, so 3.5 moles of it will have a mass of ...

3.5 mol × 229.34 g/mol = 802.69 g

8 0

3 years ago

The energy of a photon needed to cause ejection of an electron from a photoemissive metal is expressed as the sum of the binding

slega [8]

Answer:

$Binding\ energy=43.43\times 10^{-20}\ J$

Explanation:

Using the expression for the photoelectric effect as:

$E=h\nu_0+\frac {1}{2}\times m\times v^2$

Also, $E=\frac {h\times c}{\lambda}$

$\nu_0=\frac {c}{\lambda_0}$

Applying the equation as:

$\frac {h\times c}{\lambda}=\frac {hc}{\lambda_0}+\frac {1}{2}\times m\times v^2$

Where,

h is Plank's constant having value $6.626\times 10^{-34}\ Js$

c is the speed of light having value $3\times 10^8\ m/s$

$\lambda$ is the wavelength of the light being bombarded

Given, $\lambda=4.00\times 10^{-7}\ m$

$\frac {hc}{\lambda_0}$ is the binding energy or threshold energy

$\frac {1}{2}\times m\times v^2$ is the kinetic energy of the electron emitted. = $6.26\times 10^{-20}\ J$

Thus, applying values as:

$\frac{h\times c}{\lambda}=Binding\ Energy+Kinetic\ Energy$

$\frac{6.626\times 10^{-34}\times 3\times 10^8}{4.00\times 10^{-7}}\ J=Binding\ Energy+6.26\times 10^{-20}\ J$

$\frac{19.878}{10^{19}\times \:4}\ J=Binding\ Energy+6.26\times 10^{-20}\ J$

$49.69\times 10^{-20}\ J=Binding\ Energy+6.26\times 10^{-20}\ J$

$Binding\ energy=43.43\times 10^{-20}\ J$

5 0

3 years ago

Which arrow in the diagram represents the burning of fossil fuels? Choose 1 answer: Choose 1 answer: (Choice A) A arrow 1 (Choic

Alona [7]

Answer: arrow 4

Explanation:

7 0

2 years ago

What is the percentage composition of each element in Fe(OH)3

Bezzdna [24]

Answer:

Fe =52.2%, O = 44.9%, H = 2.81%

Explanation:

Percentage composition is also known as percentage by mass.

First, find the Mr of the compound.

Mr of Fe(OH)₃ = 55.8 + (16 × 3) + (1 × 3)

= 106.8

Now Divide the mass of the element, as per the compound, by the Mr of the compound found and times that by 100.

% composition of Fe = $\frac{55.8}{106.8}$ × 100 = 52.2%

% composition of O = $\frac{16*3}{106.8}$ × 100 = 44.9%

[There are 3 oxygen atoms in the compound Fe(OH)₃, so we will multiply the atomic mass of oxygen with the number of atoms in the compound: 16×3 ]

% composition of H = $\frac{1*3}{106.8}$ × 100 = 2.81%

[There are 3 hydrogen atoms in the compound Fe(OH)₃, so we will multiply the atomic mass of hydrogen with the number of atoms in the compound: 1×3 ]

3 0

2 years ago

Q1. On the Kelvin scale water freezes at 273 K and boils at 373 K.<br> True <br> False

faust18 [17]

Answer:

True

Explanation:

Water boils at 373 kelvins. ... Absolute zero is –273.15° C or –459.67° F. The "size" of a one degree change in temperature is exactly the same in the Celsius and Kelvin scales, so the freezing point of water is at a temperature of 273.15 kelvins (that is, 273.15 degrees above absolute zero

8 0

3 years ago