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3 years ago

What is atomic and mass number

1 answer:

5 0

The Atomic Mass Number is the number underneath the Element symbol and it is the atomic mass of the element. You can easily find the atomic mass(or get a very close number to it) by adding the protons and neutrons together. If there are 2 protons and 2 neutrons, the atomic mass would be 4.

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a concentration solution of H2so4 is 59.4% by mass (m/m) and has a density of 1.83 g/mL. How many mL of the solution would be re

Blababa [14]

Answer: 41.5 mL

Explanation:

Molarity of a solution is defined as the number of moles of solute dissolved per liter of the solution.

$Molarity=\frac{n}{V_s}$

where,

n = moles of solute

$V_s$ = volume of solution in L

Given : 59.4 g of $H_2SO_4$ in 100 g of solution

moles of $H_2SO_4=\frac{\text {given mass}}{\text {molar mass}}=\frac{59.4g}{98g/mol}=0.61$

Volume of solution = $\frac{\text {mass of solution}}{\text {density of solution}}=\frac{100g}{1.83g/ml}=54.6ml$

Now put all the given values in the formula of molality, we get

$Molality=\frac{0.61\times 1000}{54.6ml}=11.2M$

To calculate the volume of acid, we use the equation given by neutralisation reaction:

$M_1V_1=M_2V_2$

where,

$M_1\text{ and }V_1$ are the molarity and volume of stock acid which is $H_2SO_4$

$M_2\text{ and }V_2$ are the molarity and volume of dilute acid which is $H_2SO_4$

We are given:

$M_1=11.2M\\V_1=mL\\M_2=0.30M\\V_2=1550mL$

Putting values in above equation, we get:

$11.2\times V_1=0.30\times 1550\\\\V_1=41.5mL$

Thus 41.5 mL of the solution would be required to prepare 1550 mL of a .30M solution of the acid

4 0

3 years ago

Silicon crystals are semiconductors. Which of the following is a correct reason for the increase in the conductivity of Si cryst

Flura [38]

Answer:

Explanation:

it's correct I think and hope

8 0

2 years ago

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Scientists have measured and recorded the average rainfall of an area over several years to see if there is a pattern. Which kin

tia_tia [17]

The correct answer is d

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3 years ago

How many atoms are present in 34.69 moles of Mg

shusha [124]

<span>Avogadro's number.

1 mole of any substance, molecule or element is equal to a certain amount of atom.

6.022 x 10^23 is the Avogradro's constant.

Magnesium Oxide is a compound. therefore if you have 30.3 g of it (1 mol), it will have the same number of atoms.

34.69 moles of MgO has 208.9 x 10^23 number of atoms.

2.089 x 10^25 is also a correct answer.</span><span>
</span>

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3 years ago

What is the voltage of a circuit in a toaster with 12.0 amps of current and 8.0 ohms of resistance?

3241004551 [841]

The answer is 96 volts

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3 years ago

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