What Group is this element in?

Which term refers to an electrochemical cell that uses a spontaneous redox reaction to produce an electric current?

umka21 [38]

Answer:

voltaic cell

Explanation:

3 0

3 years ago

Read 2 more answers

The thallium (present as Tl2SO4) in a 9.486-g pesticide sample was precipitated as thallium(I) iodide. Calculate the mass percen

tino4ka555 [31]

Answer: The mass percentage of $Tl_2SO_4$ is 5.86%

Explanation:

To calculate the mass percentage of $Tl_2SO_4$ in the sample it is necessary to know the mass of the solute ( $Tl_2SO_4$ in this case), and the mass of the solution (pesticide sample, whose mass is explicit in the letter of the problem).

To calculate the mass of the solute, we must take the mass of the $TlI$ precipitate. We can establish a relation between the mass of $TlI$ and $Tl_2SO_4$ using the stoichiometry of the compounds:

$moles\ of\ TlI = \frac{0.1824 g}{331.27\frac{g}{mol} } = 5.51*10^{-4}\ mol.$

Since for every mole of Tl in $TlI$ there are two moles of Tl in $Tl_2SO_4$ , we have:

$moles\ of\ Tl_2SO_4 = 2 * moles\ of\ TlI = 1,102*10^{-3}\ mol$

Using the molar mass of $Tl_2SO_4$ we have:

$mass\ of\ Tl_2SO_4 = 1,102*10^{-3}\ mol * 504.83\ \frac{g}{mol}= 0.56\ g$

Finally, we can use the mass percentage formula:

$mass\ percentage = (\frac{solute\ mass}{solution\ mass} )*100 = (\frac{mass\ of\ Tl_2SO_4}{pesticide\ sample\ mass})*100 = (\frac{0.56g}{9.486g})*100 = 5.86\%$

6 0

3 years ago

A pump contains 0.5 L of air at 203kPa. You draw back on the piston of the pump until the pressure reads 25.4kPa. What is the vo

densk [106]

<h3> Answer;</h3>

= 4.0 L

<h3>Explanation;</h3>

Boyle's law states that the volume of a fixed mass of a gas is inversely proportional to pressure at a constant temperature.

Therefore; Volume α 1/pressure

Mathematically; V α 1/P

V = kP, where k is a constant;

P1V1 = P2V2

V1 = 0.5 l, P1 =203 kPa, P2 = 25.4 kPa

V2 = (0.5 × 203 )/25.4 

 = 3.996 

 ≈ 4.0 L

6 0

3 years ago

What is the name of CH3CH2CHMgBr(CH3)?

andre [41]

Answer:

Ethyl magnesium Bromide

4 0

1 year ago

The organic compound di‑n‑butyl phthalate, C 16 H 22 O 4 ( l ) , C16H22O4(l), is sometimes used as a low‑density ( 1.046 g ⋅ mL

damaskus [11]

Answer:

36.63 Torr

Explanation:

You need to use two expressions, one for pressure and the other with the relation of density and height of the column.

For the pressure:

P = h * d * g (1)

h is height.

d density

g gravity

The second expression put a relation between the densities and height of the column so:

d1/d2 = h1/h2 (2)

let 1 be the phthalate, and 2 the mercury.

Let's calculate first the relation of density:

d1/d2 = 13.53 / 1.046 = 12.93

Now with the first expression, we can calculate the pressure so:

P = hdg

We have two compounds so,

h1d1g = h2d2g ---> gravity cancels out

From here, we can solve for h2:

h2 = h1*(d1/d2)

replacing:

h2 = 459 / 12.53

h2 = 36.63 mm

1 mmHg is 1 torr, therefore the pressure of the gas in Torr would be 36.63 Torr

8 0

3 years ago