Dec

URGENT PLEASSSEEE HELP

Vikki [24]

Answer:

0.4 * 10^-12 m

Explanation:

Frequency of the given Electromagnetic radiation is 7.50* 10^20 Hz

Speed of the electromagnetic radiation is 3*10^8 m/s

Hence wavelength is given by the formula: Speed/Frequency

Substituting the required values:

Wavelength = 3 * 10^8/7.50 * 10^20

=3/7.5 * 10^-12 = 0.4 * 10^-12 m

Hence the required wavelength of the electromagnetic radiation is 0.4*10^-12 m/s

6 0

3 years ago

How might the structure of an atom be modeled

Sergio [31]

Answer:

you can explore the structure of atoms as you add protons, neutrons, or electrons to a model and the name of the element you have created

Explanation:

8 0

3 years ago

How many grams of sodium acetate ( molar mass = 83.06 g/mol ) must be added to 1.00 Liter of a 0.200 M acetic acid solution to m

Pie

Answer: The mass of sodium acetate that must be added is 30.23 grams

Explanation:

To calculate the number of moles for given molarity, we use the equation:

$\text{Molarity of the solution}=\frac{\text{Moles of solute}}{\text{Volume of solution (in L)}}$

Molarity of acetic acid solution = 0.200 M

Volume of solution = 1 L

Putting values in above equation, we get:

$0.200M=\frac{\text{Moles of acetic acid}}{1L}\\\\\text{Moles of acetic acid}=(0.200mol/L\times 1L)=0.200mol$

To calculate the pH of acidic buffer, we use the equation given by Henderson Hasselbalch:

$pH=pK_a+\log(\frac{[\text{salt}]}{[\text{acid}]})$

$pH=pK_a+\log(\frac{[CH_3COONa]}{[CH_3COOH]})$

We are given:

$pK_a$ = negative logarithm of acid dissociation constant of acetic acid = 4.74

$[CH_3COONa]=?mol$

$[CH_3COOH]=0.200mol$

pH = 5.00

Putting values in above equation, we get:

$5=4.74+\log(\frac{[CH_3COONa]}{0.200})$

$[CH_3COONa]=0.364mol$

To calculate the mass of sodium acetate for given number of moles, we use the equation:

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$

Molar mass of sodium acetate = 83.06 g/mol

Moles of sodium acetate = 0.364 moles

Putting values in above equation, we get:

$0.364mol=\frac{\text{Mass of sodium acetate}}{83.06g/mol}\\\\\text{Mass of sodium acetate}=(0.364mol\times 83.06g/mol)=30.23g$

Hence, the mass of sodium acetate that must be added is 30.23 grams

7 0

3 years ago

3.0 g aluminum and 6.0 g of bromine react to form AlBr3 2Al+3Br2=2AlBr3 How much product would be produced? How much reagent wou

juin [17]

2Al + 3Br2 -------------> 2AlBr3

3 g Al = 0.11 mol Al.

6 g Br2 = 0.0375 mole bromine (it is diatomic). 

moles of aluminium will take part in reaction = 0.0375 X (2/3) = 0.025. 

Gram-mole of AlBr3 will be produced = 0.025 mole = 6.6682 g.
moles of Al left = 0.11 - 0.025 = 0.086

8 0

4 years ago

Does a screw change the size of the effort force, the direction of the force, or both?

Keith_Richards [23]

Well I'm thinking that it would be both.

4 0

4 years ago