How many moles of NaOH are in 25ml of .1M NaOH?

Where is the air pressure greater-- at sea level or on a mountaintop? Explain

Nady [450]

Answer:

Air pressure is greater at sea level than at the top of a mountain. The amount of air at sea level is greater than that on top of a mountain.

Explanation:

Please give thanks to all my answers and please mark as brilliant and please follow me

8 0

3 years ago

Which level of organization refers to all the types of environments in which organisms can be found?

NeX [460]

B , Biosphere is a special shell of the Earth inhabited by living organisms

8 0

4 years ago

Describe an electron cloud. Then, name and explain a particular atomic model that used the concept of the electron cloud.

pochemuha

Electron cloud is the region around the nucleus in an atom where we can locate an electron.

The concept of electron cloud model was introduced by the Schrodinger and Heisenberg. According to this model, it would be difficult to know the position of the electrons in an atom and they are not particles that orbit around the nucleus. We can only expect the electrons to be present in specific areas called the electron clouds around the nucleus. It is the quantum mechanical model that used the concept of electron clouds. According to the model, the electron cloud or an orbital is a space around the nucleus in an atom where the probability of finding an electron is 90%. It explains that electrons show wave nature. It is difficult to determine the exact position and momentum of an electron in an atom.

3 0

3 years ago

a teacher divides her class into groups and assigns each group a task of measuring the mass of the same object three times.the t

RoseWind [281]

Answer:

This question lacks options, the options are:

A. Group C: 32.1 g, 35.0 g, 25.0 g

B. Group B: 25.5 g, 25.0 g, 24.8 g

C. Group A: 28.5g, 28.4 g, 28.5 g

D. Group D: 20.0 g, 25.0 g, 30.09

The answer is C. GROUP A

Explanation:

Precision in measurements refers to the degree of closeness between the repeated or measured values irrespective of how close they are to the true or accepted value, which is 25g in this case.

The precision of a measurement can be determined by simply finding the range (highest - lowest) of the measurements. The lowest range represents the most precise. The measurements for each group are:

Group C: 32.1 g, 35.0 g, 25.0 g

Range = 35.0 - 25.0 = 10g

Group B: 25.5 g, 25.0 g, 24.8 g

Range = 25.5 - 24.8 = 0.7g

Group A: 28.5g, 28.4 g, 28.5 g

Range: 28.5 - 28.4 = 0.1g

Group D: 20.0 g, 25.0 g, 30.09

Range = 30.09 - 25.0= 5.09g

Based on the ranges of the measurements in each group, one would notice that Group A has the lowest range (0.1g), hence, GROUP A is the most precise.

6 0

3 years ago

Write a balanced chemical equation for this reaction. What is the coefficient for hydrochloric acid in the reaction

Leviafan [203]

The question is incomplete, here is the complete question:

Write a balanced equation for the neutralization of calcium hydroxide by hydrochloric acid. What is the coefficient for hydrochloric acid in the reaction.

<u>Answer:</u> The balanced chemical reaction is written below and the coefficient of hydrochloric acid is 2.

<u>Explanation:</u>

Neutralization reaction is defined as the reaction in which an acid reacts with a base to produce a salt and water molecule.

Balanced chemical equation is defined as the equation in which total number of individual atoms on the reactant side will be equal to the total number of individual atoms on the product side. These equations follow law of conservation of mass.

The balanced chemical equation for the reaction of calcium hydroxide and hydrochloric acid follows:

$Ca(OH)_2+2HCl\rightarrow CaCl_2+2H_2O$

By Stoichiometry of the reaction:

1 mole of calcium hydroxide reacts with 2 moles of hydrochloric acid to produce 1 mole of calcium chloride and 2 moles of water molecule.

Hence, the balanced chemical reaction is written below and the coefficient of hydrochloric acid is 2.

8 0

4 years ago