S someone help please!!!!

Answer:

0.534

Explanation:

Mole fraction can be calculated using the formula:

Mole fraction = number of moles of solute ÷ number of moles of solvent and solute (solution).

In this question, solute is dimethyl ether while the solvent is methanol.

Mole (n) = mass (M) ÷ molar mass (MM)

Mole of solute (dimethyl ether) = 148.5 ÷ 46.07

= 3.22moles.

Mole of solvent (methanol) = 90 ÷ 32.04

= 2.81moles.

Total moles of solute and solvent = 3.22 + 2.81 = 6.03moles.

Mole fraction of dimethyl ether = number of moles of dimethyl ether ÷ number of moles of solution (dimethyl ether + methanol)

Mole fraction = 3.22/6.03

= 0.534

Answer:

Shapes suitable for humans to sit on it, three to four legs, a flat seat, and a back. Anything with such a shape is "chair", regardless of the peculiarities of its shape or its composition (what it is made of); anything without such a shape is a "not chair", even if you can sit on it. And a chair is classified as physical.

Explanation:

Explanation:

acid --> HCN

base --> KCN

now

another base NaOH is added

we know that

base will react with an acid

so

OH- + HCN ---> CN- + H20

we can see that

HCN is used up , so number of moles of HCN will decrease

CN- is being formed , so number of moles of CN- will increase.

A  false

B  false

C  false

D  true

E  false

Answer:

11.84 moles

Explanation:

We first balance the chemical equation

[tex]CoCl_{2} + F_{2} ------> CoF_{2} + Cl_{2}[/tex]

Both number of elements in the reactant side is equal to elements on the product side thus this equation is already balanced

Using mole ratio to find moles of [tex]COF_{2}[/tex]

1 mole of CoCl2 reacts with 1 mole of F2 to produce 1 mole of CoF2 and ! mole of Cl2

Mole CoCl2 = Mole CoF2 = 11.84 moles

Explanation:

the atmoc radius across the period

Answer:

0.73 mol

Explanation:

No. of moles(n)= Given mass/molar mass.

Given mass=124.7g

Molar mass of Ba(OH)2= Molar mass of (Barium+2Oxygen+2Hydrogen)=137+32+2=171g

No. of moles= 124.7g/171g=0.73 mol

Answer:

it would be E. because it would create steam from the h2o

Answer:

insertion (addition)

Explanation:

A T was added, making the sequence shift.

Answer:

N3F6

Explanation:

Tri- means three so three nitrogens and hexa- means six so six flourines.

Nitrogen and fluorine forms covalent compounds. The formula of one of their compound trinitrogen hexaflouride is N₃F₆.

Covalent compounds are formed by the sharing of electrons between two atoms. Atoms which are electron deficient forms covalent compounds. The number of shared electron is based on the valency of each bonded atom.

Nitrogen is 7th element in periodic table and it have five valence electrons. Thus it needs 3 more electrons to attain stability. Fluorine is 9th element with 7 electrons in its valence shell and it needs one more electron to gain stability.

In the compound trinitrogen hexafluoride, there are three nitrogens and six fluorine. Each nitrogen shares one electron with fluorine and each  fluorine in turn shares its one electron. Thus the formula of the compound is N₃F₆.

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Answer:

I t transfers from the ocean to the air, however the current is not as warm so less energy will transfer from the current to the air making ChrisstChurch cooler than usual.

waves pounding the base of the cliff

Answer:

Waves pounding off the base of the cliff

Explanation:

Answer:

Hydrogen fuel cells do not produce any CO2 emissions during operation, even if their production is not necessarily carbon-free. This gives them an advantage over combustion engine vehicles, which can emit small amounts of poisonous carbon monoxide and require well-ventilated rooms for indoor use.

Explanation:

If a large photon strikes the surface, that has enough strength to take out an electrode, which will then travel to the positive side since it is negative. Current is flowing at this stage. Since the reduced photons will be unable to distinguish between atoms, no power can pass.

Answer:

increase

Explanation:

Answer:

1. 2N₂ + O₂ ---> 2N₂O

2. BaCl₂ + 2NaOH ---> Ba(OH)₂ + 2NaCl

3. H₂SO₄ + 2KOH ----> K₂SO₄ + 2H₂O

4. K₂CO₃ + 2HCl ---> 2KCl + H₂O + CO₂

5. CaCO₃ + 2HNO₃ ---> Ca(NO₃)₂ + H₂O + CO₂

6. Ca + 2H₂O ---> Ca(OH)₂ + H₂

7. Pb(NO₃)₂ + 2NaI ---> PbI₂ + 2NaNO₃

8. Al₂(SO₄)₃ + 6NaOH ---> 2Al(OH)₃ + 3Na₂SO₄

9. Al(OH)₃ + NaOH ---> NaAlO₂ + 2H₂O

10. 2Pb(NO₃)₂ ---> 2PbO + 4NO₂ + O₂

Explanation:

A balanced equation of a chemical reaction is one that has the number of moles of atoms of each element taking part in the reaction equal on both sides of the reaction, that is on the reactants and products sides of the reaction.

The balanced equations of the given reactions is as follows:

1. 2N₂ + O₂ ---> 2N₂O

2. BaCl₂ + 2NaOH ---> Ba(OH)₂ + 2NaCl

3. H₂SO₄ + 2KOH ----> K₂SO₄ + 2H₂O

4. K₂CO₃ + 2HCl ---> 2KCl + H₂O + CO₂

5. CaCO₃ + 2HNO₃ ---> Ca(NO₃)₂ + H₂O + CO₂

6. Ca + 2H₂O ---> Ca(OH)₂ + H₂

7. Pb(NO₃)₂ + 2NaI ---> PbI₂ + 2NaNO₃

8. Al₂(SO₄)₃ + 6NaOH ---> 2Al(OH)₃ + 3Na₂SO₄

9. Al(OH)₃ + NaOH ---> NaAlO₂ + 2H₂O

10. 2Pb(NO₃)₂ ---> 2PbO + 4NO₂ + O₂

Answer: b 36 g

Explanation:

Answer:

energy due to its velocity. We can compare potential and kinetic energy by considering a car on a hill. When the car is at the top of the hill it has the most potential energy.

Answer: It will take 9.13 minutes for the sample.

Explanation:

Expression for rate law for first order kinetics is given by:

[tex]t=\frac{2.303}{k}\log\frac{a}{a-x}[/tex]

where,

k = rate constant  

t = age of sample

a = initial amount of the reactant = [tex]2.81\times 10^4[/tex]

a - x = amount left after decay process = [tex]3.52\times 10^3[/tex]

a) for completion of half life:

Half life is the amount of time taken by a radioactive material to decay to half of its original value.

[tex]t_{\frac{1}{2}}=\frac{0.693}{k}[/tex]

[tex]k=\frac{0.693}{3.05min}=0.227min^{-1}[/tex]

b) for activity to decrease from 2.81E4 Ci to 3.52E3 Ci:

[tex]t=\frac{2.303}{0.227}\log\frac{2.81\times 10^4}{3.52\times 10^3}[/tex]

[tex]t=9.13min[/tex]

Thus it will take 9.13 minutes for the sample.

[tex]t_{99.9}=40min[/tex]

The time after which 99.9% reactions gets completed is 40 minutes

Answer:

In a combustion reaction, a substance reacts with oxygen from the air. Combustion reactions happen at high temperatures, and transfer energy to the surroundings as light and heat. ... Since methane is made up of atoms of carbon and hydrogen, the products of its combustion reaction are oxides of carbon and hydrogen.

Explanation:

Answer:

C6H12O2

Explanation:

The Jones reagent is a reagent in organic chemistry used to convert primary alcohols to carboxylic acids and secondary alcohols to ketones. Recall that tertiary alcohols can not be oxidized.

The compound  2-methyl-2,3-pentandiol contains one secondary and one tertiary alcohol. The secondary alcohol is oxidized to a ketone while the tertiary alcohol is not oxidized.

Hence the product of the oxidation using Jones reagent is 2-Hydroxy-2-methyl-3-pentanone with the molecular formula C6H12O2.

Answer:

1710 cm^-1

Explanation:

The Infrared spectrum of the starting material  will have a peak present at 1710 cm^-1.  this is because

2-methylcyclohexanone has a ketone group (C=O) which will be  reduced to an alcohol group (O-H), in the product i.e. (2-methylcyclohexanol). therefore the peak for the stretching vibration of the ketone carbonyl (C=O) is present only in the starting material only .and  The peak for the stretching is at 1710 cm^-1

Answer:

Explanation:

When you divide exponentials, you subtract the powers. For the numbers infront, just use a basic calculator for.

7.95/6.02 = 1.32

10^22/10^23 = 10^-1

1.32 x 10^-1 is your answer

Answer:

0.0011 moles

Explanation:

Recall that;

Number of moles = mass of substance/ molar mass of the substance

Mass of asprin = 0.2001 g

Molar mass of asprin = 180.158 g/mol

Number of moles =  0.2001 g/180.158 g/mol

Number of moles = 0.0011 moles

Answer:

B) valence electrons.

Explanation:

Valence electrons can be defined as the number of electrons present in the outermost shell of an atom. Valence electrons are used to determine whether an atom or group of elements found in a periodic table can bond with others. Thus, this property is typically used to determine the chemical properties of elements.

For example, oxygen has a total number of eight (8) electrons while neon has total number of ten (10) electrons. Therefore, an atom of oxygen is able to gain (receive) two (2) more electrons in order to have the same electron arrangements as the noble gas i.e an atom of neon with an atomic number of 10.

Basically, each free electrons (valence electrons) produces a covalent bond.

Hence, single, double, or triple covalent bonds in a carbon atom are formed from valence electrons.

Single, double, or triple covalent bonds in a carbon atom are formed from Valency electrons.

The valency electron are the electrons found in the outermost shell of an

atom.

The valency electron of an atom determines the kind of bonding that exist in

an element .

Neutral Carbon atoms has 6 electrons . The number of valency electrons

(electrons in the outermost shell) in Carbon is 4 valency electrons.

So, carbon can form covalent bond by sharing electrons  with other atom of

an element. The bonding maybe single, double or triple bonds .

This bonding are formed by the electrons in the outermost shell(valency electrons)

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