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3 years ago

What did the Curies demonstrate by studying pitchblende?

Chemistry

2 answers:

mylen [45]3 years ago

5 0

Answer:

a on edge

Explanation:

Mekhanik [1.2K]3 years ago

3 0

Answer:

A- Uranium is not only the radioactive element

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What volume (in L) of oxygen will be required to produce 77.4 L of water vapor in the reaction below?

Inga [223]

Answer:

90.3 L

Explanation:

Given data:

Volume of water produced = 77.4 L

Volume of oxygen required = ?

Solution:

Chemical equation:

2C₂H₆ + 7O₂ → 4CO₂ + 6H₂O

It is known that,

1 mole = 22.414 L

There are 7 moles of oxygen = 7×22.414 = 156.9 L

There are 6 moles of water = 6×22.414 = 134.5 L

Now we will compare:

H₂O : O₂

134.5 : 156.9

77.4 : 156.9/134.5×77.4 =90.3 L

So for the production of 77.4 L water 90.3 L oxygen is required.

8 0

3 years ago

staci is attending a music festival. the ticket to the festival costs $87.96, Staci pleans to purchase $30.00 t-shirts from the

ziro4ka [17]

The total amount that Staci had in hand is $200.00.

The ticket at that time costs $87.96.

One Tshirt costs, $30.00.

Now that she has paid ticket, she will deduct the ticket from the cash she has in hand, so as to know the amount she is remaining with.

Tha is, $200-$87.96 = $112.04.

∴ In hand Staci has $112.04 extra cash whereby she can purchase more t shirts.

To get the number of tshirt she can buy, she will divide the amount she has in hand by the amount per piece of t shirt.

For example, $112.04 / $30 = $3.73.

∴ Staci can only purchase threet shirts only at a total cost of $90 for all the t shirts which is $30 × 3 = $90.

Staci has excess of 22.04 after deducting ticket and the other amount she has used to purchase the extra t shirts.

That is, $112.04 - $90 = $22.04.

3 0

3 years ago

Read 2 more answers

Human body cells are made by doing what ?

frozen [14]

Answer:

When cells become damaged or die the body makes new cells to replace them. This process is called cell division. One cell doubles by dividing into two. Two cells become four and so on.

Explanation:

6 0

3 years ago

4) list 3 protest rights you have that are protected under the law. How can you protect these rights? George Floyd’s ?

Pavel [41]

Peaceful Protest, Signing Pettitons, contacting mayors/governors and writing emails/sending letters

7 0

3 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

3 years ago