During a scientific investigation, which step will a scientist perform first?

What is created when an acid is mixed with a base?

Arturiano [62]

Answer:

If you mix equal amounts of a strong acid and a strong base, the two chemicals essentially cancel each other out and produce a salt and water. Mixing equal amounts of a strong acid with a strong base also produces a neutral pH (pH = 7) solution.

8 0

3 years ago

A reaction was performed in which 3.6 g 3.6 g of benzoic acid was reacted with excess methanol to make 1.3 g 1.3 g of methyl ben

Anit [1.1K]

Answer: The percent yield of the reaction is 32.34 %

Explanation:

To calculate the number of moles, we use the equation:

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$ .....(1)

For benzoic acid:

Given mass of benzoic acid = 3.6 g

Molar mass of benzoic acid = 122.12 g/mol

Putting values in equation 1, we get:

$\text{Moles of benzoic acid}=\frac{3.6g}{122.12g/mol}=0.0295mol$

The chemical equation for the reaction of benzoic acid and methanol is:

$\text{Benzoic acid + methanol}\rightarrow \text{methyl benzoate}$

By Stoichiometry of the reaction

1 mole of benzoic acid produces 1 mole of methyl benzoate

So, 0.0295 moles of benzoic acid will produce = $\frac{1}{1}\times 0.0295=0.108$ moles of methyl benzoate

Now, calculating the mass of methyl benzoate from equation 1, we get:

Molar mass of methyl benzoate = 136.15 g/mol

Moles of methyl benzoate = 0.0295 moles

Putting values in equation 1, we get:

$0.0295mol=\frac{\text{Mass of methyl benzoate}}{136.15g/mol}\\\\\text{Mass of methyl benzoate}=(0.0295mol\times 136.15g/mol)=4.02g$

To calculate the percentage yield of methyl benzoate, we use the equation:

$\%\text{ yield}=\frac{\text{Experimental yield}}{\text{Theoretical yield}}\times 100$

Experimental yield of methyl benzoate = 1.3 g

Theoretical yield of methyl benzoate = 4.02 g

Putting values in above equation, we get:

$\%\text{ yield of methyl benzoate}=\frac{1.3g}{4.02g}\times 100\\\\\% \text{yield of methyl benzoate}=32.34\%$

Hence, the percent yield of the reaction is 32.34 %

6 0

3 years ago

The standard cell potential of the following galvanic cell is 1.562 V at 298 K. Zn(s) | Zn2+(aq) || Ag+(aq) | Ag(s) What is the

myrzilka [38]

Answer:

E = 1.602v

Explanation:

Use the Nernst Equation => E(non-std) = E⁰(std) – (0.0592/n)logQc …

Zn⁰(s) => Zn⁺²(aq) + 2 eˉ

2Ag⁺(aq) + 2eˉ=> 2Ag⁰(s)

_____________________________

Zn⁰(s) + 2Ag⁺(aq) => Zn⁺²(aq) + 2Ag(s)

Given E⁰ = 1.562v

Qc = [Zn⁺²(aq)]/[Ag⁺]² = (1 x 10ˉ³)/(0.150)² = 0.044

E = E⁰ -(0.0592/n)logQc = 1.562v – (0.0592/2)log(0.044) = 1.602v

4 0

3 years ago

Read 2 more answers

What are the conditions needed for reaction to happen in aldehydes and ketones?

miv72 [106K]

Explanation:

You may not realise it, but you come across aldehydes and ketones many times a day. Take cakes and biscuits, for example. Their golden, caramelised crust is formed thanks to the Mailliard reaction. This is a process that occurs at temperatures above 140° C, when sugars with the carbonyl group in foods react with nucleophilic amino acids to create new and complex flavours and aromas.

Another example is formaldehyde. Correctly known as methanal, it is the most common aldehyde in industry. It has multiple uses, such as in tanning and embalming, or as a fungicide. However, we can also react it with different molecules to make a variety of more useful compounds. These include polymers, adhesives and precursors to explosives. But how do aldehydes and ketones react, and why?You should remember from Aldehydes and Ketones that they both contain the carbonyl functional group , . This is a carbon atom joined to an oxygen atom by a double bond. Let's take a closer look at it.

If we compare the electronegativities of carbon and oxygen, we can see that oxygen is a lot more electronegative than carbon.

7 0

2 years ago

What stress will shift the following equilibrium system to the left?

Alona [7]

Answer: Increasing temperature

Explanation:

The Principle of Le Chatelier states that if a system in equilibrium is subjected to a change of conditions, it will move to a new position in order to counteract the effect that disturbed it and recover the state of equilibrium.

The variation of one or several of the following factors can alter the equilibrium condition in a chemical reaction:

Temperature
The pressure
The volume
The concentration of reactants or products

In the case of the reaction in the question, the change that moves the balance to the left will be the one that moves it towards the reagents, that is, that favors the production of reagents instead of products.

Decreasing the concentration of SO3 and increasing the concentration of SO2 will favor the production of SO3, which is the product of the reaction.
Decreasing the volume increases the pressure of the system and the balance will move to where there is less number of moles. In the case of the reaction in question, we have 3 moles of molecules in the reactants (1 mole of O2 + 2 moles of SO2) while in the products there are 2 moles of SO3 only, therefore, decreasing the volume will displace the balance to the right, which corresponds to the sense in which there is less number of moles.

The reaction of the question is an exothermic since ΔH <0, therefore in the reaction heat is produced and it can be written in the following way,

2SO2(g) + O2(g) ⇌ 2SO3(g) + heat

So, if we increase the temperature we will be adding heat to the system, so the balance would move to the left to compensate for the excess heat in the system.

5 0

3 years ago