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3 years ago

What is the solution to the problem expressed to he correct number of significant figures? 12.0/7.11

Chemistry

1 answer:

Law Incorporation [45]3 years ago

6 0

Answer: The solution to the problem expressed to he correct number of significant figures is 1.69

Explanation:

Significant figures : The figures in a number which express the value -the magnitude of a quantity to a specific degree of accuracy is known as significant digits.

The rule applied for multiplication and division is :

The least precise number determines the number of significant figures in the answer.

As 12.0 has 3 significant digits and 7.11 also has 3 significant digits, the answer would also contain 3 significant digits.

For $\frac{12.0}{7.11}=1.69$

Thus the solution to the problem expressed to he correct number of significant figures is 1.69

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We want to calculate the concentrations of all species in a 0.58 M Na 2 SO 3 (sodium sulfite) solution. The ionization constants

NeX [460]

Explanation:

Reaction equation is as follows.

$Na_{2}SO_{3}(s) \rightarrow 2Na^{+}(aq) + SO^{2-}_{3}(aq)$

Here, 1 mole of $Na_{2}SO_{3}$ produces 2 moles of cations.

$[Na^{+}] = 2[Na_{2}SO_{3}] = 2 \times 0.58$

= 1.16 M

$[SO^{2-}_{3}] = [Na_{2}SO_{3}]$ = 0.58 M

The sulphite anion will act as a base and react with $H_{2}O$ to form $HSO^{-}_{3}$ and $OH^{-}$ .

As, $K_{b} = \frac{K_{w}}{K_{a_{2}}}$

= $\frac{10^{-14}}{6.3 \times 10^{-8}}$

= $1.59 \times 10^{-7}$

According to the ICE table for the given reaction,

$SO^{2-}_{3} + H_{2}O \rightleftharpoons HSO^{-}_{3} + OH^{-}$

Initial: 0.58 0 0

Change: -x +x +x

Equilibrium: 0.58 - x x x

So,

$K_{b} = \frac{[HSO^{-}_{3}][OH^{-}]}{[SO^{2-}_{3}]}$

$1.59 \times 10^{-7} = \frac{x^{2}}{0.58 - x}$

$x^{2} = 1.59 \times 10^{-7} \times (0.58 - x)$

x = 0.0003 M

So, x = $[HSO^{-}_{3}] = [OH^{-}]$ = 0.0003 M

$[SO^{2-}_{3}]$ = 0.58 - 0.0003

= 0.579 M

Now, we will use $[HSO^{-}_{3}]$ = 0.0003 M

The reaction will be as follows.

$HSO^{2-}_{3} + H_{2}O \rightleftharpoons H_{2}SO_{3} + OH^{-}$

Initial: 0.0003

Equilibrium: 0.0003 - x x x

$K_{b} = \frac{x^{2}}{0.0003 - x}$

$K_{b} = \frac{K_{w}}{K_{a_{1}}}$

= $\frac{10^{-14}}{1.4 \times 10^{-2}}$

= $7.14 \times 10^{-13}$

Therefore, $7.14 \times 10^{-13} = \frac{x^{2}}{0.0003 - x}$

As, x <<<< 0.0003. So, we can neglect x.

Therefore, $x^{2} = 7.14 \times 10^{-13} \times 0.0003$

= $0.00214 \times 10^{-13}$

x = $0.0146 \times 10^{-6}$

x = $[OH^{-}] = [H_{2}SO_{3}]$ = $1.46 \times 10^{-8}$

$[H^{+}] = \frac{10^{-14}}{[OH^{-}]}$

= $\frac{10^{-14}}{0.0003}$

= $3.33 \times 10^{-11}$ M

Thus, we can conclude that the concentration of spectator ion is $3.33 \times 10^{-11}$ M.

5 0

3 years ago

How many double bonds does CCL2H2 have?

galben [10]

None. Both chlorines and both hydrogens are single-bonded to the central carbon atom; the molecule is comprised of four single bonds and no double bonds.

Hope this helps!

4 0

2 years ago

Which of the following best describes the difference in bonding between two hydrogen atoms and two carbon atoms?

valentinak56 [21]

Answer :

2. Hydrogen forms bonds through the overlap of 1s atomic orbitals and the sharing of electrons between atoms. Carbon forms bonds through the overlapping of sp hybrid atomic orbitals and the sharing of electrons between carbon atoms.

Explanation:

The H-H bond is formed by the overlap of two 1s orbitals and the sharing of electrons between the two atoms.

A carbon atom must use the overlap of hybridized atomic orbitals and the sharing of electrons to bond with another carbon atoms.

1. is wrong because H can use only its 1s orbital for bonding.

3. is wrong because C must share electrons to form a carbon-carbon bond.

4. is wrong because C does NOT use overlapping of 2s orbitals for bonding. It uses the overlap of hybridized orbitals.

5. is wrong because H must share electrons to form an H-H bond.

4 0

3 years ago

The coordination sphere of a complex consists of ________. The coordination sphere of a complex consists of ________. the ligand

sammy [17]

Answer:

The coordination sphere of a complex consists of the central metal ion and the ligands bonded to it.

Explanation:

The Coordination Compounds are sets of a central metal ion attached to a group of molecules or ions that surround it. They are also called metal complexes or simply complexes. Then they are compounds that have a central atom surrounded by a group of molecules or ions, the latter called ligands.

The central atom must have empty orbitals capable of accepting pairs of electrons, with the transition metals being the ones with the greatest tendency. Because of this, they can act as Lewis acids (electron pair acceptors). The ligands have unshared electron pairs, then acting as Lewis bases (electron pair donors).

When forming a complex, it is said that the ligands coordinate to the metal and the central metal and the ligands attached to it constitute the coordination sphere of the complex.

Finally, the coordination sphere of a complex consists of the central metal ion and the ligands bonded to it.

5 0

3 years ago

6 How many moles are in a 321 g sample of magnesium?

Tatiana [17]

Answer:

13.4mol of Mg

Explanation:

Given parameters:

Mass of magnesium = 321g

Unknown:

Number of moles = ?

Solution:

The number of moles of a substance is given as;

Number of moles = $\frac{mass}{molar mass}$

Molar mass of Mg = 24g/mol

Insert the parameters and solve;

Number of moles = $\frac{321}{24}$ = 13.4mol of Mg

3 0

2 years ago