The table below lists the densities of some common materials at 20 degrees Celsius.

Calculate the volume of a 0.5M solution containing 20g of NaOH

Tju [1.3M]

Answer:

1L

Explanation:

First, let us calculate the number of mole present in 20g of NaOH. This is illustrated below:

Mass = 20g

Molar Mass of NaOH = 23 + 16 + 1 = 40g/mol

Number of mole =?

Number of mole = Mass /Molar Mass

Number of mole of NaOH = 20/40 = 0.5mol

From the question given, we obtained the following data:

Molarity = 0.5M

Mole = 0.5mole

Volume =?

Molarity = mole /Volume

Volume = mole /Molarity

Volume = 0.5/0.5

Volume = 1L

6 0

3 years ago

Read 2 more answers

In science, we like to develop explanations that we can use to predict the outcome of events and phenomena. Try to develop an ex

Kay [80]

The question is incomplete. The complete question is :

In science, we like to develop explanations that we can use to predict the outcome of events and phenomena. Try to develop an explanation that tells how much NaOH needs to be added to a beaker of HCl to cause the color to change. Your explanation can be something like: The color change will occur when [some amount] of NaOH is added because the color change occurs when [some condition]. The goal for your explanation is that it describes the outcome of this example, but can also be used to predict the outcome of other examples of this phenomenon. Here's an example explanation: The color of the solution will change when 40 ml of NaOH is added to a beaker of HCl because the color always changes when 40ml of base is added. Although this explanation works for this example, it probably won't work in examples where the flask contains a different amount of HCl, such as 30ml. Try to make an explanation that accurately predicts the outcome of other versions of this phenomenon.

Solution :

Consider the equation of the reaction between NaOH and $HCl$

NaOH (aq) + HCl (aq) → NaCl(aq) + $H_2O (l)$

The above equation tells us that $1 \text{mole}$ of $NaOH$ reacts with $1 \text{mole}$ of $HCl$ .

So at the equivalence point, the moles of NaOH added = moles of $HCl$ present.

If the volume of the $HCl$ taken = $V_1$ mL and the conc. of $HCl$ = $M_1$ mole/L

The volume of NaOH added up to the color change = $V_2 \text{ and conc of NaOH = M}_2$ mole/L

Moles of $HCl$ taken = $V_1 \ mL \times M_1 \ mol/100 \ mL = V_2M_2 \times 10^{-3}$ moles.

The color change will occur when the moles of NaOH added is equal to the moles of $HCl$ taken.

Thus when $V_1 M_1 \times 10^{-3} = V_2M_2 \times 10^{-3}$

or when $V_1M_1 = V_2M_2$

or $V_2=\frac{V_1M_1}{M_2}$ mL of NaOH added, we observe the color change.

Where $V_1, M_1$ are the volume and molarity of the $HCl$ taken.

$M_2$ is the molarity of NaOH added.

When both the NaOH and $HCl$ are of the same concentrations, i.e. if $M_1=M_2$ , then $V_2=V_1$

Or the 40 mL of $HCl$ will need 40 mL of NaOH for a color change and

30 mL of $HCl$ would need 30 mL of NaOH for the color change (provided the concentration $M_1=M_2$ )

7 0

2 years ago

What are the two types of alleles? A: Dominant and recessive B: genotype and phenotype C: Gene and chromosome or D: Gene and DNA

ololo11 [35]

Answer:

dominant and recessive

Explanation:

4 0

3 years ago

Acidic solutions have pH value less than 7 . Select one : O True O False

Marina CMI [18]

Answer:

Explanation:

The answer is true.

8 0

2 years ago

Read 2 more answers

Solid calcium carbonate breaks down into carbon dioxide gas, oxygen gas, and solid calcium, write an equation for described reac

Savatey [412]

Answer:

CaCO₃ ------> CaO + CO₂

<em>Note: The breakdown products of solid calcium carbonate is not carbon dioxide gas, oxygen gas, and solid calcium. Rather, it is calcium oxide and carbon dioxide as shown in the reaction equation above.</em>

Explanation:

Calcium carbonate is a mineral which occurs in nature in rocks as calcite and limestone. It is also the main component of eggshells, snail shells, seashells and pearls. It has the molecular formula CaCO₃.

Calcium carbonate or limestone decomposes into calcium oxide and carbon dioxide when heated and the reaction is used to make quicklime and carbon dioxide gas. The equation of the reaction is given below:

CaCO₃ ------> CaO + CO₂

Calcium oxide, one of the products of The decomposition reaction is known as lime and is an important mineral used for many purposes such as reducing the acidity of soils, in the production of limelight, as well as serving as the main ingredient in cement.

The main use of calcium carbonate is in the construction industry as an ingredient of cement. Calcium carbonate is also an important mineral required by sea organisms for making their shells.

5 0

2 years ago