Hi, you've asked an incomplete question. Here's the diagram that completes the question.
Answer:
<u>(B) nonpolar covalent bonds</u>
Explanation:
This structure in the diagram rightly fits the description of a non-covalent bond because there is an equal sharing of electrons of Carbon (C) and Chlorine (Cl).
<em>Remember</em> too that these elements are in their solid-state, hence the CCl4 (carbon tetrachloride) molecules are held strongly together.
Mole - one of the most important concepts in chemistry - is a kind of link to go from the microworld of atoms and molecules in a normal macrocosm grams and kilograms.
In chemistry often have to consider large numbers of atoms and molecules. For fast and efficient calculation made using the weighing method. But it is necessary to know the weight of individual atoms and molecules. In order to identify the molecular weight must be added the weight of all atoms in the compound.
Answer:
- <u><em>It is positive when the bonds of the product store more energy than those of the reactants.</em></u>
Explanation:
The <em>standard enthalpy of formation</em>, <em>ΔHf</em>, is defined as the energy required to form 1 mole of a substance from its contituent elements under standard conditions of pressure and temperature.
Then, per defintion, when the elements are already at their standard states, there is not energy involved to form them from that very state; this is, the standard enthalpy of formation of the elements in their standard states is zero.
It is not zero for the compounds in its standard state, because energy should be released or absorbed to form the compounds from their consituent elements. Thus, the first choice is false.
When the bonds of the products store more energy than the those of the reactants, the difference is:
- ΔHf = ΔHf products - ΔHf reactants > 0, meaning that ΔHf is positive. Hence, the second statement is true.
Third is false because forming the compounds may require to use (absorb) or release (produce) energy, which means that ΔHf could be positive or negative.
Fourth statement is false, because the standard state of many elements is not liquid. For example, it is required to supply energy to iron to make it liquid. Thus, the enthalpy of formation of iron in liquid state is not zero.
Answer:
1.68% is ionized
Explanation:
The Ka of benzoic acid, C₇H₆O₂, is 6.46x10⁻⁵, the equilibrium in water of this acid is:
C₇H₆O₂(aq) + H₂O(l) ⇄ C₇H₅O₂⁻(aq) + H₃O⁺(aq)
Ka = 6.46x10⁻⁵ = [C₇H₅O₂⁻] [H₃O⁺] / [C₇H₆O₂]
<em>Where [] are concentrations in equilibrium</em>
In equilibrium, some 0.225M of the acid will react producing both C₇H₅O₂⁻ and H₃O⁺, the equilibrium concentrations are:
[C₇H₆O₂] = 0.225-X
[C₇H₅O₂⁻] = X
[H₃O⁺] = X
Replacing:
6.46x10⁻⁵ = [X] [X] / [0.225-X]
1.4535x10⁻⁵ - 6.46x10⁻⁵X = X²
1.4535x10⁻⁵ - 6.46x10⁻⁵X - X² = 0
Solving for X:
X = -0.0038. False solution, there is no negative concentrations.
X = 0.00378M. Right solution.
That means percent ionization (100 times Amount of benzoic acid ionized over the initial concentration of the acid) is:
0.00378M / 0.225M * 100 =
<h3>1.68% is ionized</h3>
Answer: If the solubility of sodium chloride is 36 grams per 100 grams of water then 5.8 moles of NaCl dissolved in 1 L of water solution would be considered unsaturated.
Explanation:
A solution which contains the maximum amount of solute is called a saturated solution. Whereas a solution in which more amount of solute is able to dissolve is called an unsaturated solution.
Now, the number of moles present in 36 g of NaCl (molar mass = 58.4 g/mol) is as follows.
This shows that solubility of sodium chloride is 36 grams per 100 grams of water means a maximum of 0.616 mol of NaCl will dissolve in 100 mL of water.
So, a solution in which number of moles of NaCl are less than 0.616 mol per 100 mL then the solution formed will be an unsaturated solution.
- As 5.8 moles of NaCl dissolved in 1 L (or 1000 mL) of water. So, moles present in 100 mL are calculated as follows.
- Moles present in 100 mL of water for 3.25 moles of NaCl dissolved in 500 ml in water are as follows.
- Moles present in 100 mL of water for 1.85 moles of NaCl dissolved in 300 ml of water are as follows.
Thus, we can conclude that if the solubility of sodium chloride is 36 grams per 100 grams of water then 5.8 moles of NaCl dissolved in 1 L of water solution would be considered unsaturated.
