Ask question

Ask question

All categories

3 years ago

9

30 pts! Sodium and water react according to the following equation. If 31.5g of sodium are added to excess water, how many liter

s of hydrogen gas are formed at STP? Show all work for credit. 2Na+2H2O--> 2NaOH+H2

1 answer:

mihalych1998 [28]3 years ago

3 0

First, calculate the number of moles of sodium present with the given mass,

31.5 g of sodium x (1 mol sodium/ 23 g sodium) = 1.37 mol sodium

It is given in the equation that for every 2mols of sodium, one mol of H2 is produced.

mols of H2 = (1.37 mols sodium)(1 mol H2/ 2 mols sodium)
mols of H2 = 0.685 mols H2

Then, at STP, 1 mol of gas = 22.4 L.

volume of H2 = (0.685 mols H2)(22.4 L / 1 mol)
volume of H2 = 15.34 L

Answer: 15.34 L

You might be interested in

When the following oxidation–reduction reaction in acidic solution is balanced, what is the lowest whole-number coefficient for

ruslelena [56]

Answer:

b. 16, reactant side

Explanation:

Let's consider the following redox reaction.

MnO₄⁻(aq) + I⁻(aq) → Mn²⁺(aq) + I₂(s)

We can balance it using the ion-electron method.

Step 1: Identify both half-reactions

Reduction: MnO₄⁻(aq) → Mn²⁺(aq)

Oxidation: I⁻(aq) → I₂(s)

Step 2: Perform the mass balance, adding H⁺(aq) and H₂O(l) where appropriate

MnO₄⁻(aq) + 8 H⁺(aq) → Mn²⁺(aq) + 4 H₂O(l)

2 I⁻(aq) → I₂(s)

Step 3: Perform the charge balance, adding electrons where appropriate

MnO₄⁻(aq) + 8 H⁺(aq) + 5 e⁻ → Mn²⁺(aq) + 4 H₂O(l)

2 I⁻(aq) → I₂(s) + 2 e⁻

Step 4: Multiply both half-reactions by numbers so that the number of electrons gained and lost are equal

2 × (MnO₄⁻(aq) + 8 H⁺(aq) + 5 e⁻ → Mn²⁺(aq) + 4 H₂O(l))

5 × (2 I⁻(aq) → I₂(s) + 2 e⁻)

Step 5: Add both half-reactions and cancel what is repeated on both sides

2 MnO₄⁻(aq) + 16 H⁺(aq) + 10 e⁻ + 10 I⁻(aq) → 2 Mn²⁺(aq) + 8 H₂O(l) + 5 I₂(s) + 10 e⁻

The balanced reaction is:

2 MnO₄⁻(aq) + 16 H⁺(aq) + 10 I⁻(aq) → 2 Mn²⁺(aq) + 8 H₂O(l) + 5 I₂(s)

5 0

2 years ago

Start with 100.00 mL of 0.10 M acetic acid, CH3COOH. The solution has a pH of 2.87 at 25 oC. a) Calculate the Ka of acetic acid

jasenka [17]

Answer: a) The $K_a$ of acetic acid at $25^0C$ is $1.82\times 10^{-5}$

b) The percent dissociation for the solution is $4.27\times 10^{-3}$

Explanation:

$CH_3COOH\rightarrow CH_3COO^-H^+$

cM 0 0

$c-c\alpha$ $c\alpha$ $c\alpha$

So dissociation constant will be:

$K_a=\frac{(c\alpha)^{2}}{c-c\alpha}$

Give c= 0.10 M and $\alpha$ = ?

Also $pH=-log[H^+]$

$2.87=-log[H^+]$

$[H^+]=1.35\times 10^{-3}M$

$[CH_3COO^-]=1.35\times 10^{-3}M$

$[CH_3COOH]=(0.10M-1.35\times 10^{-3}=0.09806M$

Putting in the values we get:

$K_a=\frac{(1.35\times 10^{-3})^2}{(0.09806)}$

$K_a=1.82\times 10^{-5}$

b) $\alpha=\sqrt\frac{K_a}{c}$

$\alpha=\sqrt\frac{1.82\times 10^{-5}}{0.10}$

$\alpha=4.27\times 10^{-5}$

$\% \alpha=4.27\times 10^{-5}\times 100=4.27\times 10^{-3}$

5 0

3 years ago

Write chemical equations for the following electrolytes dissolving in water

Elden [556K]

$1)NaCl=>Na^{+}+Cl^{-}\\2)PbSO_{4}=>Pb^{2+}+SO_(4)^{2-}$

6 0

2 years ago

How many moles of CO2 are emitted into the atmosphere when 22.1 g C8H18 is burned

ANTONII [103]

Answer:

1.552 moles

Explanation:

First, we'll begin by writing a balanced equation for the reaction showing how C8H18 is burn in air to produce CO2.

This is illustrated below:

2C8H18 + 25O2 -> 16CO2 + 18H2O

Next, let us calculate the number of mole of C8H18 present in 22.1g of C8H18. This is illustrated below:

Molar Mass of C8H18 = (12x8) + (18x1) = 96 + 18 = 114g/mol

Mass of C8H18 = 22.1g

Mole of C8H18 =..?

Number of mole = Mass /Molar Mass

Mole of C8H18 = 22.1/144

Mole of C8H18 = 0.194 mole

From the balanced equation above,

2 moles of C8H18 produced 16 moles of CO2.

Therefore, 0.194 mole of C8H18 will produce = (0.194x16)/2 = 1.552 moles of CO2.

Therefore, 1.552 moles of CO2 are emitted into the atmosphere when 22.1 g C8H18 is burned

8 0

3 years ago

Boling water is considered as

professor190 [17]

Answer:Boiling water is a physical change, as it rearranges molecules but does not affect the internal structures. Boiling water forces the water molecules away from each other as the liquid changes to vapor. In a chemical change, new chemical substances are created or formed. Advertisement. Physical changes affect the state of an item, and a chemical change happens at a molecular level.

Explanation:

hope it helps:))

4 0

2 years ago