solve this question please! it have 3 options which one of them is correct option​

A magnesium ribbon is cleaned to remove the protective layer of basic magnesium carbonate from its surface, so that it may readily combine with the oxygen in air (on heating).

Answer:

Magnesium gets covered with a layer of magnesium oxide when kept in air for a long time. This layer hinders the burning of magnesium. Hence, it is to be cleaned before burning.

Answer:

E.....Na2I.,.

Explanation:

Cuz sodium has a Vallency..1......lodide has Vallency 2

Answer:

I'm pretty sure this is propanediol

Explanation:

I'm not sure how to explain it, but I believe this is the structure for propanediol. Please let me know if I misunderstood and don't hesitate to reach out with questions!

1,3-propan-diol is the chemical name the given structure: [tex]HOCH_2CH_2CH_2OH[/tex].

Chemical names are orderly systems for classifying and identifying various chemical compounds. They act as a benchmark for international scientific and research communication. For the development of many scientific domains, a standardised nomenclature system for chemicals must be created and adopted. Chemical names, which are made up of a combination of words and symbols, include detailed information on the make-up and structure of a certain substance. They frequently contain constituents, functional groups, and distinct modifiers that aid in describing the compound's varied attributes. 1,3-propan-diol is the chemical name the given structure: [tex]HOCH_2CH_2CH_2OH[/tex].

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Answer:

theory

Explanation:

if you assume something that you didn't see occuring it is called a theory

Answer:

B

Explanation:

because protons have a +1 charge and electrons have a -1 charge, so if an atom is neutral it must have the same amount of protons and neutrons

The question is as follows: How many oxygen molecules are produced by the decomposition of 28.5 g of H2O2 (molecular mass = 34.0g / mol) according to the equation

2H2O2 (l) → 2H2O (l) + O2 (g)

Answer: There are [tex]2.52 \times 10^{23}[/tex] molecules are produced by the decomposition of 28.5 g of [tex]H_{2}O_{2}[/tex] according to the equation [tex]2H_{2}O(l) \rightarrow 2H_{2}O(l) + O_{2}(g)[/tex].

Explanation:

Given: Mass of [tex]H_{2}O_{2}[/tex] = 28.5 g

As moles is the mass of a substance divided by its molar mass. Hence, moles of [tex]H_{2}O_{2}[/tex] is calculated as follow.

[tex]Moles = \frac{mass}{molarmass}\\= \frac{28.5 g}{34.0 g/mol}\\= 0.838 mol[/tex]

According to the given equation, 2 moles of [tex]H_{2}O_{2}[/tex] gives 1 mole of [tex]O_{2}[/tex]. So, moles of [tex]O_{2}[/tex] produced by 0.838 moles of [tex]H_{2}O_{2}[/tex]  will be calculated as follows.

[tex]Moles of O_{2} = \frac{0.838 mol}{2}\\= 0.419 mol[/tex]

This means that moles of [tex]O_{2}[/tex] produced is 0.419 mol.

As per the mole concept, 1 mole of every substance has [tex]6.022 \times 10^{23}[/tex] molecules.

So, molecules of [tex]O_{2}[/tex] present in 0.419 mole are as follows.

[tex]0.419 \times 6.022 \times 10^{23}\\= 2.52 \times 10^{23}[/tex]

Thus, we can conclude that there are [tex]2.52 \times 10^{23}[/tex] molecules are produced by the decomposition of 28.5 g of [tex]H_{2}O_{2}[/tex] according to the equation [tex]2H_{2}O(l) \rightarrow 2H_{2}O(l) + O_{2}(g)[/tex].

Answer:

because they are high reactive to the air thats why we keep them in paroffin oil

housefly

Explanation:

Because it one of the affective vector of disease carrier and it always roam towards wastes and dirty materials likely to get attracted . And it carries contagious disease from hospitals , infected patients , etc .

Answer:

huh what?

Explanation:

Is  196,96657  u

I hope I've helped :)

Answer:

Wavelength = 0.049 m

Explanation:

Given that,

The frequency of a wave,[tex]f=6.1\times 10^9\ Hz[/tex]

We need to find the wavelength of the wave. We know that,

[tex]c=f\lambda\\\\\lambda=\dfrac{c}{f}\\\\\lambda=\dfrac{2.998 \times 10^8}{6.1\times 10^9}\\\\\lambda=0.049\ m[/tex]

So, the wavelength of the wave is 0.049 m.

Answer:

thnx for the points too muchee

Explanation:

Answer:

Explanation:

[tex]{hope it helps}}[/tex]

Answer:

pCH₄ = 0.540 atm

pC₂H₆ = 0.405 atm

pC₃H₈ = 0.505 atm

Explanation:

Step 1: Calculate the total number of gaseous moles

n = n(CH₄) + n(C₂H₆) + n(C₃H₈)

n = 0.320 mol + 0.240 mol + 0.300 mol = 0.860 mol

Step 2: Calculate the partial pressure of each gas

We will use the following expression.

pi = P × Χi

where,

pCH₄ = 1.45 atm × 0.320 mol/0.860 mol = 0.540 atm

pC₂H₆ = 1.45 atm × 0.240 mol/0.860 mol = 0.405 atm

pC₃H₈ = 1.45 atm × 0.300 mol/0.860 mol = 0.505 atm

Answer:

Liquid

Explanation:

Quite an easy question!

Answer:

Liquid

Explanation:

I was passing by lol

Answer:

kevin is right according to what i see

Answer:

1: because phosphate contain oxide ions so that is base character

Answer:

If there were multiple products, we can take each product and mixed with a sample of a pure compound that we suspect might be the same as the product. Then, we taking the melting point of this mixture that contains one of our product and pure sample. Then, we can observe the change in melting point, if there is no change in melting point or the melting stays in the same range of the pure compound. Then, the that product along with the pure sample are actually the same compound, not a mixture of two compounds. However, if the melting point for our pure sample compound changed or didn't stay in the same range after the mixing with on of our products. then we can conclude that this product and the pure sample are completely different compound, and indeed they are a mixture.

Answer:

0.723 moles (5 s.f.)

Explanation:

Whenever there is a chemical equation, ensure that it is balanced. This is because a balanced chemical equation tells us the mole ratio (not the ratio of their masses), which means the relationship of the number of moles of reactants or products with one another.

The chemical equation given has already been balanced. Looking at the coefficients of HBr and Ba(OH)₂, the mole ratio of HBr to Ba(OH)₂ is 2: 1.

• 1 mole of Ba(OH)₂ is needed to react with 2 mole of HBr

Find the number of moles of HBr present:

Number of moles= mass ÷mr

Amount of HBr

= 117 ÷(1 +79.9)

= 1.4462 moles (5 s.f.)

Since the amount of Ba(OH)₂ required is half the amount of HBr present,

amount of Ba(OH)₂ required

= 1.4462 ÷2

= 0.723 moles (3 s.f.)

Notes:

• mr

= relative molecular mass

= sum of relative atomic masses (which can be found in the periodic table) in a molecule

[tex]\huge\fcolorbox{red}{pink}{Answer ♥}[/tex]

Life on Earth is based on carbon, likely because each carbon atom can form bonds with up to four other atoms simultaneously. This quality makes carbon well-suited to form the long chains of molecules that serve as the basis for life as we know it, such as proteins and DNA.

Hope it helps uh ✌️✌️✌️

Answer:

4.95L

Explanation:

Using Charle's law equation;

V1/T1 = V2/T2

Where;

V1 = initial volume (L)

V2 = final volume (L)

T1 = initial temperature (K)

T2 = final temperature (K)

According to the question, the following information was given:

V1 = 4.50L

V2 = ?

T1 = 27°C = 27 + 273 = 300K

T2 = 57°C = 57 + 273 = 330K

Using V1/T1 = V2/T2

4.50/300 = V2/330

Cross multiply

300 × V2 = 4.5 × 330

300V2 = 1485

V2 = 1485 ÷ 300

V2 = 4.95L

Answer:

Petroleum refinery capacity in the UAE 2009-2018

In 2018, the total production capacities of all refineries in the UAE were 1.13 metric barrels per day. Total total production capacity of the al-Ruwais refinery in the United Arab Emirates was approximately 817,000 metric barrels per day.

Answer:

What are your given options? I can't answer unless I know those :)

Explanation:

Answer:

1. Isotope with mass number 39.

2. 39.02g/mol

Explanation:

1. The most common isotope is the isotope in the higher proportion, that is:

Isotope with mass number 39.

2. The average atomic mass is the sum of the masses times their abundance. For the element X:

Average atomic mass:

38*0.0967 + 39*0.7868 + 40*0.1134 + 41*0.0031

= 39.02g/mol

Answer: the answer is C

IF U MIGHT NEED AN EXPLANATION FEEL FREE TO COMMENT

The laboratory equipment like the burette, pipette, and measuring cylinders are used in process of titration process. The solution of NaOH is added by the burette. Thus, option C is correct.

Titration has been the analytical technique that uses the known and measured quantity of the solution to estimate the volume of another solution with an unknown volume and known molar concentration.

The laboratory equipment like burette, pipette, and measuring cylinders are used in measuring the volume in the titration process. The burette is filled with sodium hydroxide to measure its quantity.

The pipette is used to transfer the volume of the solution that is known (hydrochloric acid) and the measuring cylinder is used to measure the liquid (water) that is used in chemistry experiments.

Therefore, option C. pipette, burette, and measuring cylinder are the apparatus used in the titration process.

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Answer:

i hope it will help you

Explanation:

there will be 7 electrons and 9 protons will have 2+ charge.

Answer:

1. False

2. True

3. False

4. False

5. True

6. False

7. True

8. True

9. True

Answer:

When the two atoms are in contact, potassium readily transfers its outer electron to chlorine which readily accepts it, resulting in both atoms achieving a state of eight outermost electrons. With this electron transfer, the ionic bond in KCl is formed.

Answer:

A standard system of measurement is very important because it helps us from making mistakes at the moment of doing calculations and correctly working...

Answer:

A standard measurement system is important because it allows scientists to compare data and communicate with each other about their results. Metric System – is a measurement system based on the number 10.

Answer:

all i can accurately say is that 2 and 4 are both true

Answer:

c

Explanation:

Nh4OH + HCL ---> NH4Cl + H3O

so ph decreases as H3O increases

and OH also decreases

When NH4OH is added to a solution with HCI, the pH of the solution B ) increases as the OH- concentration increases.

NH₄OH is a strong base as a result of the presence of the OH compound which is a base as well. Bases have high pH and acids have low pH.

This means that as the OH- concentration increases, the solution is being made to be more basic which would lead to the pH rising.

In conclusion, option B is correct.

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