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4 years ago

Which phrase best describes a scientists?

Chemistry

1 answer:

larisa86 [58]4 years ago

8 0

Answer:

They are helpers of the world who find out about the natural world and try to explain what they have observed.

Explanation:

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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

water stored in snow and ice can return directly to the atmosphere through the process of sublimation. please select the best an

My name is Ann [436]

Answer:

the answer is True i just took the test

Explanation:

5 0

4 years ago

If 5.4 moles of Fe react with 4.7 moles of O2, what is the maximum amount of Fe2O3 (in moles) that can be produced? What is the

DIA [1.3K]

Answer:

2.7 moles of Fe₂O₃ is the maximum amount that can be produced. Iron is the limiting reactant.

Explanation:

The balanced reaction is:

4 Fe + 3 O₂ → 2 Fe₂O₃

By reaction stoichiometry (that is, the relationship between the amount of reagents and products in a chemical reaction), the following amounts of each compound participate in the reaction:

Fe: 4 moles
O₂: 3 moles
Fe₂O3: 2 moles

The limiting reagent is one that is consumed first in its entirety, determining the amount of product in the reaction. When the limiting reagent is finished, the chemical reaction will stop.

You can use a simple rule of three as follows: if by stoichiometry 4 moles of Fe reacts with 3 moles of O₂, how much moles of Fe will be needed if 4.7 moles of O₂ react?

$moles of Fe =\frac{4. moles of Fe*4.7 moles of O_{2}}{3 moles of O_{2} }$

moles of O₂= 6.27

But 6.27 moles of Fe are not available, 5.4 moles are available. Since you have less moles than you need to react with 4.7 moles of O₂, iron Fe will be the limiting reagent.

So you can use a simple rule of three as follows: if by stoichiometry 4 moles of Fe produce 2 moles of Fe₂O₃, how many moles of Fe₂O₃ will be produced if 5.4 moles of Fe react?

$moles of Fe_{2}O_{3}=\frac{5.4 moles of Fe*2 moles of Fe_{2} O_{3} }{4 moles of Fe}$

moles of Fe₂O₃= 2.7 moles

Then:

2.7 moles of Fe₂O₃ is the maximum amount that can be produced. Iron is the limiting reactant.

4 0

3 years ago

Define natural resources

Sav [38]

Answer:

THOSE RESOURCES THAT ARE FOUND IN NATURE ARE CALLED NATURAL RESOUCES

3 0

3 years ago

The Chinese first began recording astronomical observations about 2,000 years ago.

UNO [17]

The answer is false

4 0

3 years ago