What is the name of the element with the atomic number 79

A sample containing 16.93 metal pellets is poured into a graduated cylinder containing 11.2 of water, causing the water level in

mixer [17]

Answer:

<h3>The answer is 1.99 g/mL</h3>

Explanation:

The density of a substance can be found by using the formula

$density = \frac{mass}{volume} \\$

From the question

mass = 16.93 g

volume = final volume of water - initial volume of water

volume = 19.7 - 11.2 = 8.5 mL

We have

$density = \frac{16.93}{8.5} \\ = 1.9917647058...$

We have the final answer as

Hope this helps you

7 0

3 years ago

Which of the following statements about protons are true?

attashe74 [19]

The second on it true

4 0

2 years ago

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If 21.00 mL of a 0.68 M solution of C6H5NH2 required 6.60 mL of the strong acid to completely neutralize the solution, what was

Andru [333]

Answer:

pH = 2.46

Explanation:

Hello there!

In this case, since this neutralization reaction may be assumed to occur in a 1:1 mole ratio between the base and the strong acid, it is possible to write the following moles and volume-concentrations relationship for the equivalence point:

$n_{acid}=n_{base}=n_{salt}$

Whereas the moles of the salt are computed as shown below:

$n_{salt}=0.021L*0.68mol/L=0.01428mol$

So we can divide those moles by the total volume (0.021L+0.0066L=0.0276L) to obtain the concentration of the final salt:

$[salt]=0.01428mol/0.0276L=0.517M$

Now, we need to keep in mind that this is an acidic salt since the base is weak and the acid strong, so the determinant ionization is:

$C_6H_5NH_3^++H_2O\rightleftharpoons C_6H_5NH_2+H_3O^+$

Whose equilibrium expression is:

$Ka=\frac{[C_6H_5NH_2][H_3O^+]}{C_6H_5NH_3^+}$

Now, since the Kb of C6H5NH2 is 4.3 x 10^-10, its Ka is 2.326x10^-5 (Kw/Kb), we can also write:

$2.326x10^{-5}=\frac{x^2}{0.517M}$

Whereas x is:

$x=\sqrt{0.517*2.326x10^{-5}}\\\\x=3.47x10^-3$

Which also equals the concentration of hydrogen ions; therefore, the pH at the equivalence point is:

$pH=-log(3.47x10^{-3})\\\\pH=2.46$

Regards!

6 0

2 years ago

During an experiment, a scientist places a heat lamp above a bowl of water and uses the lamp to heat up the water. How does heat

dlinn [17]

Answer:

Radiation

Explanation:

6 0

2 years ago

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A chemist measures the amount of hydrogen gas produced during an experiment. She finds that 264. g of hydrogen gas is produced.

Lesechka [4]

Answer:

The answer is 130.953 g of hydrogen gas.

Explanation:

Hydrogen gas is formed by two atoms of hydrogen (H), so its molecular formula is H₂. We can calculate is molecular weight as the product of the molar mass of H (1.008 g/mol):

Molecular weight H₂= molar mass of H x 2= 1.008 g/mol x 2= 2.01568 g

Finally, we obtain the number of mol of H₂ there is in the produced gas mass (264 g) by using the molecular weight as follows:

mass= 264 g x 1 mol H₂/2.01568 g= 130.9731703 g

The final mass rounded to 3 significant digits is 130.973 g

4 0

2 years ago