Ask question

Ask question

All categories

3 years ago

10

A solution of NaOH has a concentration of 25.00% by mass. What mass of NaOH is present in 0.250 g of this solution? Use the peri

odic table in the toolbar if needed.

2 answers:

meriva3 years ago

7 0

The concentration of NaOH is 25.00% by mass, it means that 25.00% of the mass of the solution is of NaOH. Hence:

$m_{NaOH}=25.00\%\times m_{solution}\Longrightarrow m_{NaOH}=\dfrac{25}{100}\times 0.250~g\iff\\\\\boxed{m_{NaOH}=0.0625~g}$

Ulleksa [173]3 years ago

5 0

Answer : The mass of NaOH present in the solution is, 0.0625 grams

Explanation : Given,

Mass % = 25 %

Mass of solution = 0.250 g

Formula used :

$Mass\%=\frac{\text{Mass of}NaOH}{\text{Mass of solution}}\times 100$

Now put all the given values in this formula, we get the mass of NaOH.

$25=\frac{\text{Mass of}NaOH}{0.250g}\times 100$

$\text{Mass of}NaOH=0.0625g$

Therefore, the mass of NaOH present in the solution is, 0.0625 grams

You might be interested in

If red is the color on the top of the spectrum being emitted from the prism, what is the color on the bottom?

Elan Coil [88]

Answer:

violet

Explanation:

hope this helps!

5 0

2 years ago

How much heat is absorbed when 447 g of water , Cp = 4.184 J/goC, goes from 25.0 oC to 35.0 oC?

Digiron [165]

Answer:

The answer to your question is Q = 18702.5 J

Explanation:

Data

mass of water = m = 447 g

Cp = 4.184 J/g°C

Temperature 1 = T1 = 25°C

Temperature 2 = T2 = 35°C

Heat = Q = ? Joules

Process

1.- Write the formula to calculate heat

Q = mCp(T2 - T1)

2.- Substitution

Q = (447)(4.184)(35 - 25)

3.- Simplification

Q = (447)(4.184)(10)

4.- Result

Q = 18702.5 J

8 0

3 years ago

The monatomic ions of Groups 1A(1) and 7A(17) are all singly charged. In what major way do they differ? Why?

insens350 [35]

<u>Answer:</u> Group 1 ions are known as cations and Group 17 ions are known as anions.

<u>Explanation:</u>

Ions are formed when an atom looses or gains electrons.

If an atom gains electrons, it leads to the formation of negative ions known as anions. <u>For Example:</u> Fluorine is a Group 17 element which gains 1 electron to form $F^-$ ions.

If an atom looses electrons, it leads to the formation of positive ions known as cations. <u>For Example:</u> Sodium is a Group 1 element which looses 1 electron to form $Na^+$ ions.

Hence, group 1 ions are known as cations and Group 17 ions are known as anions.

3 0

3 years ago

Read 2 more answers

how many molecules of sulfuric acid are in a spherical raindrop of diameter 6.0 mm if the acid rain has a concentration of 4.4 *

Vitek1552 [10]

Answer:

The number of moles =

$Moles=4.97\times 10^{-8}$

The number of molecules =

$Molecules = 2.99\times 10^{16}$

Explanation:

Volume of the sphere is given by :

$V=\frac{4}{3}\pi r^{3}$

here, r = radius of the sphere

$radius=\frac{diameter}{2}$

$radius=\frac{6.0}{2}$

Radius = 3 mm

r = 3 mm

1 mm = 0.01 dm (1 millimeter = 0.001 decimeter)

3 mm = 3 x 0.01 dm = 0.03 dm

r = 0.03 dm

<em>("volume must be in dm^3 , this is the reason radius is changed into dm"</em>

<em>"this is done because 1 dm^3 = 1 liter and concentration is always measured in liters")</em>

$V=\frac{4}{3}\pi 0.03^{3}$

$V=\frac{4}{3}\pi 2.7\times 10^{-5}$

$V=1.13\times 10^{-4}dm^{3}$

$V=1.13\times 10^{-4}L$ (1 L = 1 dm3)

Now, concentration "C"=

$C=4.4\times 10^{-4}moles/liter$

The concentration is given by the formula :

$C=\frac{moles}{Volume(L)}$

This is also written as,

$Moles = C\times Volume$

$Moles=1.13\times 10^{-4}\times 4.4\times 10^{-4}$

$Moles=4.97\times 10^{-8}$ moles

One mole of the substance contain "Na"(= Avogadro number of molecules)

So, "n" mole of substance contain =( n x Na )

$N_{a}=6.022\times 10^{23}$

Molecules =

$Molecule=4.97\times 10^{-8}\times 6.022\times 10^{23}$

$Molecules = 2.99\times 10^{16}$ molecules

7 0

3 years ago

How many moles are present in 107 g of sodium?

cricket20 [7]

Answer:

i think 4.65 moles......

7 0

3 years ago

Read 2 more answers