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4 years ago

Water and minerals move up the xylem because of a vacuum created by _____.

Chemistry

1 answer:

Galina-37 [17]4 years ago

4 0

Answer:

The right answer is B) evaporation

Explanation:

Transpiration occurs at the leaf surface which is the loss of water due to the evaporation. This phenomenon works as trigger of water and mineral movement above to the xylem. Due to the evaporation of water at the leaf, negative pressure is created at the surface of leaf. Tension is produced which results in the pull of water from roots up to the xylem vessels.

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A sample may contain any or all of the following ions: Hg22+, Ba2+, Mn2+. No precipitate formed when an aqueous solution of NaCl

Bess [88]

Answer:

Only Mn⁺² is present.

Explanation:

When an aqueous solution of NaCl is added, the Cl⁻ species is introduced. In the presence of Cl⁻, Hg₂²⁺ would precipitate as Hg₂Cl₂.

When an aqueous solution of Na₂SO₄ is added, the SO₄⁻² species is introduced. In the presence of SO₄⁻², Ba⁺² would precipitate as BaSO₄.

No precipitate formed when either of these solutions were added, thus the sample does not contain Hg₂⁺² nor Ba⁺².

Under basic conditions Mn⁺² would precipitate as Mn(OH)₂. A precipitate formed once the solution was made basic, so the sample contains Mn⁺².

3 0

3 years ago

The burning of methane gas, given below, is a redox reaction. which part of the reaction illustrates oxidation?

Effectus [21]

The burning of methane gas, given below, is a redox reaction. which part of the reaction illustrates oxidation, Ch4+O2---CO2+H2OCH4---CO2

8 0

3 years ago

1. If there are 100 navy beans, 27 pinto beans and 173 blackeyed peas in a container, what is the percent abundance in the conta

kompoz [17]

The answers to the two questions are:

1. The percent abundance in the container which has 100 navy, 27 pinto, and 173 black-eyed peas beans is 33.3%, 9.0%, and 57.7% for navy bean, pinto bean, and black-eyed peas beans, respectively.

2. The weighted average score for the scores of 85, 75, 96 obtained from the evaluations of exams (20%), labs (75%), and homework (96%) is 84.1.

1. The percent abundance by type of bean is given by:

$\% = \frac{n}{n_{t}} \times 100$ (1)

Where:

n: is the number of each type of beans

$n_{t}$ : is the total number of beans

The total number of beans can be calculated by adding the number of all the types of beans:

$n_{t} = n_{n} + n_{p} + n_{b}$ (2)

Where:

$n_{n}$ : is the number of navy beans = 100

$n_{p}$ : is the number of pinto beans = 27

$n_{b}$ : is the number of black-eyed peas beans = 173

Hence, the total number of beans is (eq 2):

$n_{t} = 100 + 27 + 173 = 300$

Now, the percent abundance by type of bean is (eq 1):

Navy beans

$\%_{n} = \frac{100}{300} \times 100 = 33.3 \%$

Pinto beans

$\%_{p} = \frac{27}{300} \times 100 = 9.0 \%$

Black-eyed peas beans

$\%_{b} = \frac{173}{300} \times 100 = 57.7 \%$

Hence, the percent abundance by type of bean is 33.3%, 9.0%, and 57.7% for navy bean, pinto bean, and black-eyed peas beans, respectively.

2. The average score (S) can be calculated as follows:

$S = e*\%_{e} + l*\%_{l} + h*\%_{h}$ (3)

Where:

e: is the score for exams = 85

l: is the score for lab reports = 75

h: is the score for homework = 96

$%_{e}$ $\%_{e}$ : is the percent for exams = 70.0%

$\%_{l}$ : is the percent for lab reports = 20.0%

$\%_{h}$ : is the percent for homework = 10.0%

Then, the average score is:

$S = 85*0.70 + 75*0.20 + 96*0.10 = 84.1$

We can see that if the score for each evaluation is 100, after multiplying every evaluation for its respective percent, the final average score would be 100.

Therefore, the weighted average score will be 84.1.

Find more about percents here:

brainly.com/question/255442?referrer=searchResults

brainly.com/question/22444616?referrer=searchResults

I hope it helps you!

4 0

3 years ago

Identify the term that matches each electrochemistry definition.

anygoal [31]

Answer: a. Cathode

b. Galvanic cell

c. Anode

d. Electrolytic cell

e. half reaction

Explanation:

Galvanic cell or Electrochemical cell is defined as a device which is used for the conversion of the chemical energy produced in a spontaneous redox reaction into the electrical energy.

Electrolytic cell is a device where electrical energy is used to drive a non spontaneous chemical reaction.

In the electrochemical cell, the oxidation occurs at an anode which is a negative electrode and the reduction occurs at the cathode which is a positive electrode. Thus the electrons are produced at anode and travel towards cathode.

The balanced two-half reactions will be:

Oxidation half reaction : $M\rightarrow M^{n+}+ne^-$

Reduction half reaction : $N^{n+}+ne^-\rightarrow N$

Thus the overall reaction will be: $M+N^{n+}\rghtarrow M^{n+}+N$

4 0

3 years ago

5. In general, how are word equations written to describe chemical reactions?

Len [333]

Answer is: Reactants and products are written in words; reactants are on the left, products are on the right side of reaction.

For example, balanced chemical reaction for cellular respiration (convert biochemical energy):

C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O or:

glucose + oxygen → carbon dioxide + water.

Glucose and oxygen are reactants and carbon dioxide and water are products of reaction.

This reaction is exothermic (energy is released).

Word equation is a chemical reaction expressed in words rather than chemical formulas.

8 0

3 years ago