All categories

2 years ago

Multi-Step Conversions (Always go through moles!)

Chemistry

1 answer:

Annette [7]2 years ago

8 0

Mass of water needed : 96.3 g

<h3>Further explanation </h3>

A mole is a number of particles(atoms, molecules, ions) in a substance

This refers to the atomic total of the 12 gr C-12 which is equal to 6.02.10²³, so 1 mole = 6.02.10²³ particles

Can be formulated :

N = n x No

N = number of particles

n = mol

No = 6.02.10²³ = Avogadro's number

moles H₂O=

$\tt moles=\dfrac{N}{No}\\\\moles=\dfrac{3.22\times 10^{24}}{6.02\times 10^{23}}\\\\moles=5.35$

mass H₂O(MW=18 g/mol) :

$\tt mass=moles\times MW\\\\mass=5.35\times 18\\\\mass=96.3~g$

You might be interested in

8. If a sample of chloroform is initially at 25°C, what is its final temperature if 150.0 g of chloroform

sashaice [31]

Answer:

The final temperature is 31.95° C.

Explanation:

Given that,

Initial temperature of a sample of chloroform, $T_i=25^{\circ} C$

Mass of chloroform, m = 150 g

It absorbs 1 kJ of heat, Q = 10³ J

The specific heat of chloroform, c = 00.96 J/gºC

We need to find the final temperature. The heat absorbed by an object in terms of specific heat is given by :

$Q=mc\Delta T\\\\Q=mc(T_f-T_i)\\\\\dfrac{Q}{mc}+T_i=T_f\\\\T_f=\dfrac{10^3}{150\times 0.96}+25\\\\=31.95^{\circ} C$

So, the final temperature is 31.95° C.

5 0

2 years ago

A solid mass of 25g is added to a solution with the mass of 60g. The final mass of the solution is 75g. Explain why the mass of

Ann [662]

It is not equal because it dose not obey the conservation of mass. 60+25= 85 not 75.

4 0

2 years ago

Describe the main differences beA human cell has 46 chromosomes. At the end of mitosis, there are two cells, each with 46 chromo

liberstina [14]

Answer:

At the end of meiosis, there are four cells, each with 23 chromosomes, for a total of 92 chromosomes split between the four cells.

Explanation:

During meiosis, a diploid cell (46 chromosomes) replicates its DNA (making 92 chromosomes) then undergoes two cell divisions to generate four haploid cells (23 chromosomes).

These haploid cells are the gametes which, during fertilization, fuse to become a zygote with 46 chromosomes.

6 0

2 years ago

If the molar absorptivity constant for the red dye solution is 5.56×104 M-1cm-1, calculate the molarity of the red dye solution

Shtirlitz [24]

Explanation:

a) Using Beer-Lambert's law :

Formula used :

$A=\epsilon \times c\times l$

where,

A = absorbance of solution = 0.945

c = concentration of solution = ?

l = length of the cell = 1.20 cm

$\epsilon$ = molar absorptivity of this solution = $5.56\times 10^4 M^{-1} cm^{-1}$

$0.945=5.56\times 10^4 M^{-1} cm^{-1}\times 1.20 \times c$

$c=1.4163\times 10^{-5} M=14.16 \mu M$

( $1\mu M=10^{-6} M$ )

14.16 μM is the molarity of the red dye solution at the optimal wavelength 519nm and absorbance value 0.945.

b) $c=1.4163\times 10^{-5} mol/L$

1 L of solution contains $1.4163\times 10^{-5}$ moles of red dye.

Mass of $1.4163\times 10^{-5}$ moles of red dye:

$1.4163\times 10^{-5}\times 879.86g/mol=0.01246 g$

$(w/v)\%=\frac{\text{Mass of solute (g)}}{\text{Volume of solvent (mL)}}\times 100$

$red(w/v)\%=\frac{0.01246 g}{1000 mL}\times 100=0.001246\%$

c) In order to dilute red dye solution by 5 times, we will need to add 1 L of water to solution of given concentration.

Concentration of red dye solution = $c=1.4163\times 10^{-5} M$

Concentration of red solution after dilution = c'

$c=c'\times 5$

$1.4163\times 10^{-5} M=c'\times 5$

$c'=2.83\times 10^{-6} M$

The final concentration of the diluted solution is $2.83\times 10^{-6} M$

8 0

2 years ago

Will give most brainly.

Anna [14]

Answer:

One mole

Explanation:

It tells u the concentration

8 0

1 year ago