Diatomic gases such as H2(g), O2(g), and N2(g) contain _______

Please show work: Question below

ozzi

Answer:

b) 2.0 mol

Explanation:

Given data:

Number of moles of Ca needed = ?

Number of moles of water present = 4.0 mol

Solution:

Chemical equation:

Ca + 2H₂O → Ca(OH)₂ + H₂

now we will compare the moles of Ca and H₂O .

H₂O : Ca

2 : 1

4.0 : 1/2×4.0 = 2.0 mol

Thus, 2 moles of Ca are needed.

3 0

3 years ago

A 100.0 mL solution containing 0.864 g of maleic acid (MW=116.072 g/mol) is titrated with 0.276 M KOH. Calculate the pH of the s

Lilit [14]

Answer:

pH = 1.32

Explanation:

H₂M + KOH ------------------------ HM⁻ + H₂O + K⁺

This problem involves a weak diprotic acid which we can solve by realizing they amount to buffer solutions. In the first deprotonation if all the acid is not consumed we will have an equilibrium of a wak acid and its weak conjugate base. Lets see:

So first calculate the moles reacted and produced:

n H₂M = 0.864 g/mol x 1 mol/ 116.072 g = 0.074 mol H₂M

54 mL x 1L / 1000 mL x 0. 0.276 moles/L = 0.015 mol KOH

it is clear that the maleic acid will not be completely consumed, hence treat it as an equilibrium problem of a buffer solution.

moles H₂M left = 0.074 - 0.015 = 0.059

moles HM⁻ produced = 0.015

Using the Henderson - Hasselbach equation to solve for pH:

ph = pKₐ + log ( HM⁻/ HA) = 1.92 + log ( 0.015 / 0.059) = 1.325

Notes: In the HH equation we used the moles of the species since the volume is the same and they will cancel out in the quotient.

For polyprotic acids the second or third deprotonation contribution to the pH when there is still unreacted acid ( Maleic in this case) unreacted.

3 0

3 years ago

How many molecules in each sample? 64.7 g N2 83 g CCl4 19 g C6H12O6

lilavasa [31]

Answer:

1.39x10²⁴ molecules N₂

.25x10²³ molecules CCl₄

6.38x10²² molecules C₆H₁₂O₆

Explanation:

First we convert the given masses into moles, using the compounds' respective molar mass:

64.7 g N₂ ÷ 28 g/mol = 2.31 mol N₂

83 g CCl₄ ÷ 153.82 g/mol = 0.540 mol CCl₄

19 g C₆H₁₂O₆ ÷ 180 g/mol = 0.106 mol C₆H₁₂O₆

Then we multiply each amount by Avogadro's number, to calculate the number of molecules:

2.31 mol N₂ * 6.023x10²³ molecules/mol = 1.39x10²⁴ molecules

0.540 mol CCl₄ * 6.023x10²³ molecules/mol = 3.25x10²³ molecules

0.106 mol C₆H₁₂O₆ * 6.023x10²³ molecules/mol = 6.38x10²² molecules

3 0

3 years ago

Column A 1. Reproduction: Reproduction 2. offspring: offspring 3. gamete: gamete 4. Budding: Budding 5. Binary fission: Binary f

7nadin3 [17]

Answer:

1. Reproduction: One or two parents, organisms make new offspring

2. Offspring: A new living organism

3. Gamete: female and male create mini-me by cell division

4. Budding: Hydra

5. Binary fission: Bacteria

6. Zygote: The original cell after egg cell and sperm cell join

7. Fragmentation/Regeneration: Sea star / Planarian

8. Mitosis: Healling and growth occurs in budding

9. Meiosis: Egg or sperm cell/ specialized cells

Explanation:

1. Reproduction is the process by which organisms make new offspring either sexually (involving two parents) or asexually (involving one parent only).

2. An Offspring is a new living organism

3. A gamete is a mature sexual reproductive cell, as a sperm or egg, that unites with another cell to form a new organism. It formed from female and male parents by cell division known as meiosis

4. Budding is a form of asexual reproduction in which a new offspring grows out from a part of the parent. It occurs in Hydra.

5. Biinary fission is a form of asexual reproduction which involves a separation of the parent into two new offspring. It commonly occurs in Bacteria

6. Zygote is the original cell formed after egg cell and sperm cell fuse.

7. Fragmentation/Regeneration: this is a form of reproduction in which a parent splits into fragments which are then able to develop into new organisms. It occurs in Sea star and Planarians

8. Mitosis is a form of cell division which a cell divides into two identical daughter cells with the same genetic components as the parent cell. It functions in healing and growth as well as in budding

9. Meiosis is a type of cell division that results in the production of sex cells or gametes. The number of chromosomes in the parent cell is halved and four gamete cells are produced. Egg or sperm cell/ specialized cells are produced by meiosis.

5 0

3 years ago

The law of conservation of mass states that mass is neither created nor destroyed during a chemical reaction. This can be gleane

GenaCL600 [577]

Answer : The total mass of oxygen gas released in the reaction will be, 12.8 grams

Explanation :

Law of conservation of mass : It states that mass can neither be created nor be destroyed but it can only be transformed from one form to another form.

This also means that total mass on the reactant side must be equal to the total mass on the product side.

The balanced chemical reaction will be,

$2MgO\rightarrow 2Mg+O_2$