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3 years ago

(01.01 MC)

Chemistry

2 answers:

Anestetic [448]3 years ago

6 0

Answer: Number of plants

Explanation:

In an experimental procedure an independent variable is the variable which can be manipulated or changed manually the effect of such changes can be observed on the dependent variable. The dependent variable is the outcome of the experiment.

According to the situation, carbon dioxide levels in the ocean water is the independent variable the effect of which can be observed on the number of plants that grow in the ocean. Number of plants that will grow in the ocean after the carbon dioxide levels increase or decrease will be the outcome of the study. Therefore, number of plants is the dependent variable.

mojhsa [17]3 years ago

4 0

Remember that a dependent variable is a variable that is being measured in a experiment so in this case your answer would be option C "plant height." Since how they are measuring plants height.

Hope this helps!

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How many milliliters of a 0.1000 M NaOH solution would be needed to neutralize a 1.0000-g sample of potassium hydrogen phthalate

7nadin3 [17]

Answer: 2) 2HCl(sq) + CaCO3(s) CaCl2(sq) + CO2(g) + H2O (l) No of moles of CaCO3 = amount of the CaCO3 (g)/mw of CaCO3 (g/mole)= 0.8085 g/100 g/mole = 0.008085

Explanation:

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2 years ago

What is the molarity of a 0.25-liter solution containing 52 grams of HBr? (1 point)

Pani-rosa [81]

2.6 M hBr

This would be the correct answer.

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3 years ago

How many molecules are in 4.2 miles of water?

viktelen [127]

Answer:

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3 years ago

I have 2 samples of solid chalk (aka calcium carbonate). Sample A has a total mass of 4.12 g and Sample B has a total mass of 19

IRINA_888 [86]

Answer:

A) Sample B has more calcium carbonate molecules

Explanation:

M = Molar mass of calcium carbonate = 100.0869 g/mol

$N_A$ = Avogadro's number = $6.022\times 10^{23}\ \text{mol}^{-1}$

For the 4.12 g sample

Moles of a substance is given by

$n=\dfrac{m}{M}\\\Rightarrow n=\dfrac{4.12}{100.0869}\\\Rightarrow n=0.0411\ \text{mol}$

Number of molecules is given by

$nN_A=0.0411\times 6.022\times 10^{23}=2.48\times 10^{22}\ \text{molecules}$

For the 19.37 g sample

$n=\dfrac{19.37}{100.0869}\\\Rightarrow n=0.193\ \text{mol}$

Number of molecules is given by

$nN_A=0.193\times 6.022\times 10^{23}=1.16\times 10^{23}\ \text{molecules}$

$1.16\times 10^{23}\ \text{molecules}>2.48\times 10^{22}\ \text{molecules}$

So, sample B has more calcium carbonate molecules.

The ratio of the elements of carbon, oxygen, calcium atoms, ions, has to be same in both the samples otherwise the samples cannot be considered as calcium carbonate. Same is applicable for impurities. If there are impurites then the sample cannot be considered as calcium carbonate.

7 0

3 years ago

A group of giraffes feeds on leaves and grasses during the daytime. Right now, it is dark out and the giraffes are not eating. I

Zanzabum

Answer:

Carbon dioxide is moving out of the living things.

Explanation:

The food materials eaten by living things contain carbon in the form of complex organic matter. When living things feed, they ingest this complex organic material into their bodies.

During the process of digestion, this complex organic material is broken down to give glucose. Glucose is the energy molecule in living things. Excess glucose in the body is stored as glycogen.

During cellular respiration, glucose is broken down to release carbon dioxide. Hence, at night when the giraffe has stopped eating, cellular respiration continues to occur and carbon dioxide is released, that is, carbon dioxide continues to move out of living things at night.

7 0

2 years ago