Answer:
0.3267 M
Explanation:
To solve this problem, first we calculate how many moles of Mn(ClO₄)₂ are contained in 23.640 g of Mn(ClO₄)₂·6H₂O.
Keep in mind that the crystals of Mn(ClO₄)₂ are hydrated, and <em>we need to consider those six water molecules when calculating the molar mass of the crystals</em>.
Molar mass of Mn(ClO₄)₂·6H₂O = 54.94 + (35.45+16*4)*2 + 6*18 = 361.84 g/mol
Now we <u>proceed to calculate</u>:
- 23.640 g Mn(ClO₄)₂·6H₂O ÷ 361.84 g/mol = 0.0653 mol Mn(ClO₄)₂·6H₂O = mol Mn(ClO₄)₂
Now we divide the moles by the volume, to <u>calculate molarity</u>:
- 200 mL⇒ 200/1000 = 0.200 L
- 0.0653 mol Mn(ClO₄)₂ / 0.200 L = 0.3267 M
Answer: The given statement is true.
Explanation: If this reaction would have occurred, then this reaction would be considered as displacement reaction.
Displacement reactions are the reaction in which more reactive element displaces the less reactive element in a chemical reaction. This is based on the reactivity of elements.
Reactivity of elements is the tendency of the elements to gain or loose electrons. The reactivity decreases down the group in a periodic table.
In the given reaction, Iodine and chlorine are the elements of the same group in the periodic table and iodine lies below chlorine in the group. So, the reactivity of iodine is less than the reactivity of chlorine.
Hence, in the given reaction, iodine will not replace chlorine because it lies below in the periodic table.
Question #1
Potasium hydroxide (known)
volume used is 25 ml
Molarity (concentration) = 0.150 M
Moles of KOH used
0.150 × 25/1000 = 0.00375 moles
Sulfuric acid (H2SO4)
volume used = 15.0 ml
unknown concentration
The equation for the reaction is
2KOH (aq)+ H2SO4(aq) = K2SO4(aq) + 2H2O(l)
Thus, the Mole ratio of KOH to H2SO4 is 2:1
Therefore, moles of H2SO4 used will be;
0.00375 × 1/2 = 0.001875 moles
Acid (sulfuric acid) concentration
0.001875 moles × 1000/15
= 0.125 M
Question #2
Hydrogen bromide (acid)
Volume used = 30 ml
Concentration is 0.250 M
Moles of HBr used;
0.25 × 30/1000
= 0.0075 moles
Sodium Hydroxide (base)
Volume used 20 ml
Concentration (unknown)
The equation for the reaction is
NaOH + HBr = NaBr + H2O
The mole ratio of NaOH : HBr is 1 : 1
Therefore, moles of NaOH used;
= 0.0075 moles
NaOH concentration will be
= 0.0075 moles × 1000/20
= 0.375 M
<h2>Question no 1:</h2><h2>Answer:</h2>
The correct answer is option A which is Sarah is correct because genetic diversity occurs over a long period of time.
<h3>Explanation:</h3>
- Genetic diversity is a large number of allelic combinations for a trait in specie in a population.
- Genetic diversity is caused due to mutations or random breeding in a specie.
- It is good for the adaptation of specie in an environment, due to diverse in genotypes and phenotype of a trait.
<h2>Question number 2:</h2><h2>Answer:</h2>
The correct answer is option B which is the species will adapt to the changes.
<h3>Explanation:</h3>
- Adaptation to an environment means changing your body in such a way to reduce the harmful affects of changing the environment on the body.
- For example, the long and thick fur of sheeps in a snowy area will protect them from cold.
- If the environment changes, the first thing a specie do is an adaptation to that change in the environment.
<h2>Question 3.</h2><h2>Answer:</h2>
The correct answer is option D which is, "The spines of a cactus protect it from animals".
<h3>Explanation:</h3>
- Adaptation to an environment means changing your body in such a way to reduce the harmful affects of changing the environment on the body.
- For example, the long and thick fur of sheeps in a snowy area will protect them from cold.
- So the plant of cactus was in danger due to animals. So the start growing spines in response to animals.
- Hence the correct answer is option D.
<h2>Question 4.</h2><h2>Answer:</h2>
The correct answer is option B which is, "Marie's plant will lean toward the sun so that it can get the most sunlight".
<h3>Explanation:</h3>
- The plant will lean towards the sun light by the mechanism of phototropism.
- Phototropism is the mechanism of growth of the plant in a specific direction in the response of light.
- There are two types of phototropism.
- One is a positive phototropism in which plant grows towards the light.
- The other is negative phototropism in which plant grows away from the light.
- In this question,the plant will do positive tropism.
<h2>Question no. 5</h2><h2>Answer:</h2>
The correct answer is option B which is, "The dodo bird could not adapt quickly to the challenges of the environment".
<h3>Explanation:</h3>
- Adaptation to an environment means changing your body in such a way to reduce the harmful affects of changing the environment on the body.
- For example, the long and thick fur of sheeps in a snowy area will protect them from cold.
- So the dodo could not adopt to the environment. For the positive adaption of survival, they should be afraid of sailors but the would not afraid of a sailor.
- Due to which they went extinct.
Remaining questions are in attached document.
Answer:
The modern understanding of an atom was developed by the quantum theory
