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3 years ago

(ii) Electrons are supplied to the external circuit. How and where is this done? [2]

Chemistry

1 answer:

pentagon [3]3 years ago

7 0

Answer:

The electrons are supplied by the species getting oxidized. They move from anode to the cathode in the external circuit. The external battery supplies the electrons. They enter through the cathode and come out through the anode

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Which of the following represents the electron configuration of rhodium

nordsb [41]

Answer:

i need a picture to solve

Explanation:

3 0

3 years ago

How much positive charge is in 0.7 kg of lithium? with each atom having 3 protons and 3 electrons. The elemental charge is 1.602

hichkok12 [17]

Explanation:

As a neutral lithium atom contains 3 protons and its elemental charge is given as $1.602 \times 10^{-19} C$ . Hence, we will calculate its number of moles as follows.

Moles = $\frac{mass}{\text{molar mass}}$

= $\frac{0.7 \times 1000 g}{7 g/mol}$

= 100 mol

According to mole concept, there are $6.023 \times 10^{23}$ atoms present in 1 mole. So, in 100 mol we will calculate the number of atoms as follows.

No. of atoms = $100 \times 6.023 \times 10^{23}$

= $6.023 \times 10^{25}$ atoms

Since, it is given that charge on 1 atom is as follows.

$3 \times 1.602 \times 10^{-19}C$

= $4.806 \times 10^{-19}C$

Therefore, charge present on $6.023 \times 10^{25}$ atoms will be calculated as follows.

$6.023 \times 10^{25} atoms \times 4.806 \times 10^{-19} C$

$28.95 \times 10^{6}C$

Thus, we can conclude that a positive charge of $28.95 \times 10^{6}C$ is in 0.7 kg of lithium.

3 0

3 years ago

How many atoms are there in 8.88 g Si?

Mariana [72]

Answer:

$\boxed {\boxed {\sf 1.90 \times 10^{23} \ atoms \ Si}}$

Explanation:

We are asked to find how many atoms are in 8.88 grams of silicon.

<h3>1. Grams to Moles </h3>

First, we convert grams to moles. We use the molar mass or the mass of 1 mole of a substance. These values are found on the Periodic Table as they are equal to the atomic masses, but the units are grams per mole instead of atomic mass units.

Look up silicon's molar mass.

Si: 28.085 g/mol

We will convert using dimensional analysis. Set up a conversion factor with the molar mass.

$\frac { 28.085 \ g \ Si}{1 \ mol \ Si}$

We are converting 8.88 grams of silicon to moles, so we multiply by this value.

$8.88 \ g \ Si *\frac { 28.085 \ g \ Si}{1 \ mol \ Si}$

Flip the fraction so the units of grams of silicon cancel.

$8.88 \ g \ Si *\frac{1 \ mol \ Si} { 28.085 \ g \ Si}$

$8.88 *\frac{1 \ mol \ Si} { 28.085 }$

$\frac {8.88} { 28.085 } \ mol \ Si$

$0.316183015845 \ mol \ Si$

<h3>2. Moles to Atoms </h3>

Next, we convert moles to atoms. We use Avogadro's Number or 6.022 × 10²³. This is the number of particles (atoms, molecules, formula units, etc.) in 1 mole of a substance. In this case, the particles are atoms of silicon.

Set up another conversion factor.

$\frac {6.022 \times 10^{23} \ atoms \ Si}{1 \ mol \ Si}$