How many moles of na2so4 are present in 284.078 grams of na2so4?
a. 2
b. 3
c. 5
d. 6

Answer:

(b)  19.9 moles

Explanation:

To convert from moles Al to moles O₂, you need to multiply the given value by the mole-to-mole ratio of each component. This ratio is constructed via the coefficients in the balanced reaction. The desired unit (moles O₂) should be placed in the numerator to allow for the cancellation of units.

2 Al₂O₃ ----> 4 Al + 3 O₂
                    ^         ^            

26.5 moles Al           3 moles O₂
---------------------  x  ----------------------  =  19.9 moles O₂
                                 4 moles Al

Answer:

The electron moved up to an energy level and has an energy of 21.72 x 10−19 J.

Explanation:

i know

Answer:

D) The electron moved up to an energy level and has an energy of 21.72 x 10−19 J.

Explanation:

I took the test and got it right.

Blocks on the periodic table will not list a mass number of elements in this scenario.

This table comprises of elements in order of their atomic number which determines their chemical properties.

It contains the atomic number but however doesn't contain the mass number of the elements.

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Answer:

The reaction absorbs energy ( + or exothermic)

Explanation:

When the temperature of a thermometer increases during a chemical reaction, then the reaction absorbs energy (+ or endothermic). Therefore, the correct option is B.

A rise in the temperature of a thermometer during a chemical reaction is a sign that the system is absorbing energy. This implies that the reaction is endothermic, meaning that energy must be supplied for it to proceed. Generally, endothermic reactions take heat from the environment and raise the temperature. Chemical bonds are broken and the process is accelerated by the absorbed energy.

Therefore, the correct option is B.

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did anyone able to look up this question

the ratio for the H is 3.9901

The vapour pressure in the water flask is 23.686 torr.

The pressure of [tex]H_2[/tex] in the flask was 713.514  torr.

Pressure is the [tex]H_2[/tex] exerting in the flask is 688.314 torr

Vapour pressure is a measure of the tendency of a material to change into the gaseous or vapour state, and it increases with temperature.

a.The vapour pressure of water is given by:

[tex]Log_{10} P =A- \frac{B}{C+T}[/tex], where T is in degree Celcius, P is in torr.

For 0-100 degree celcius, A=8.07131, B=1730.63, C=233.426

[tex]Log_{10} P = 8.07131 - \frac{1730.63}{233.426+25} =1.3745[/tex]

As T =25 degree celcius

[tex]P = 10^{1.3745} torr[/tex] =23.686 torr

b.We know that [tex]P_{total} =P_{H_2} + P_{H_2O}[/tex]

[tex]P_{total}[/tex] = Atmospheric pressure

[tex]737.2 torr = P_{H_2} +23.686 torr[/tex]

[tex]P_{H_2} = 713.514 torr[/tex]

c.After there is a leak in the gas collection tube, the amount at pressure due to water vapour remains unchanged as it is a quantity dependent on temperature.

[tex]P_{total} =P_{H_2} + P_{H_2O} + P_{leaking \;air}[/tex]

[tex]737.2 torr = P_{H_2} + 23.686 torr + 25.2 torr[/tex]

[tex]P_{H_2} =688.314 torr[/tex]

For calculating molar mass of any gas:

M= Density X (RT ÷ P)

M= 0.714 g X ([tex]8.314 J mol^{-1}K^{-1}[/tex]273 K ÷ 101325 Pa)

M= 15.994 g/mol = 16 g/mol.

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Answer: 3 methylhexane

Explanation: Attached is a picture of the molecule. Courtesy of the National Institute of Health, United States Government.

Answer: 3-methylhexane

Explanation:

The parent chain is six carbon atoms long, so there is the prefix 'hex'

There is a methyl branch on the third carbon atom, so it is 3-methylhexane.

Answer:

Season 5 lol

Explanation:

Answer:

season 1

Explanation:

the man was shot rip

Considering the definition of molar mass, the moles of gas used are 10.625 moles.

The molar mass of substance is a property defined as its mass per unit quantity of substance, in other words, molar mass is the amount of mass that a substance contains in one mole.

Natural gas has a molar mass of 16.0 g/mole.

You started out the day with a tank containing 200.0 g of natural gas.  So, you can apply the following rule of three: If by definition of molar mass 16 grams are contained in 1 mole, 200 grams are contained in how many moles?

[tex]amount of moles at the beginning=\frac{200 gramsx1 mole}{16 grams}[/tex]

amount of moles at the beginning= 12.5 moles

At the end of the day, your tank contains 30.0 g of natural gas. So, you can apply the following rule of three: If by definition of molar mass 16 grams are contained in 1 mole, 30 grams are contained in how many moles?

[tex]amount of moles at the end=\frac{30 gramsx1 mole}{16 grams}[/tex]

amount of moles at the end= 1.875 moles

The number of moles used will be the difference between the number of moles used initially and the contents at the end of the day.

moles used= amount of moles at the beginning - amount of moles at the end

moles used= 12.5 moles - 1.875 moles

moles used= 10.625 moles

Finally, the moles of gas used are 10.625 moles.

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Answer:

223 g O₂

Explanation:

To find the mass of oxygen gas needed, you need to (1) convert moles Al to moles O₂ (via the mole-to-mole ratio from reaction coefficients) and then (2) convert moles O₂ to grams O₂ (via the molar mass). When writing your ratios/conversions, the desired unit should be in the numerator in order to allow for the cancellation of the previous unit. The final answer should have 3 sig figs because the given value (9.30 moles) has 3 sig figs.

4 Al + 3 O₂ ----> 2 Al₂O₃
^         ^

Molar Mass (O₂): 32.0 g/mol

9.3 moles Al          3 moles O₂              32.0 g
-------------------  x  ---------------------  x  --------------------  =  223 g O₂
                              4 moles Al               1 mole

Answer:

a) Black

b) Non-magnetic

c) No reaction with carbon disulphide.

d) i don't know sry

But i had to go through my 6th grade notes for this .____.

16.06 cm is the height of the tetra bromoethane column in the barometer in cm.

A barometer is a scientific instrument used to measure atmospheric pressure, also called barometric pressure.

Explanation:

Pressure of the liquid column=ρgh

ρ= density of the liquid

h= height of the column

g= due to gravity

the

height of the mercury column corresponding to 0.971 atm

= 0.951×76÷1atm = 73.796 cm

[tex]\rho_1h_1g=\rho_2h_2g[/tex]

2.96 g/mL x 73.796 cm =13.6 g/mL [tex]h_2[/tex]

[tex]h_2[/tex]=16.06148235 =16.06 cm

16.06 cm is the height of the tetra bromoethane column in the barometer in cm.

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0.139 moles of plutonium are present in a sample containing 8.4 x 10²² atoms of Pt.

The number of moles of a substance can be calculated using the following expression:

no of moles = no of molecules ÷ 6.02 × 10²³

According to this question, 8.4 × 10²² atoms of plutonium are present in the molecule of plutonium.

no of moles = 8.4 × 10²² = 6.02 × 10²³

no of moles = 1.39 × 10-¹

no of moles = 0.139moles

Therefore, 0.139 moles of plutonium are present in a sample containing 8.4 x 10²² atoms of Pt.

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Answer: Are people happier if they have more spare time?

Explanation:

Happiness cannot be measured quantitatively.

Answer:

Explanation:The ratio of Coulomb force to gravitational force for an electron and a proton is given as,

r

1

​

=

R

2

Gm

1

​

m

2

​

​

4πε

0

​

1

​

×

R

2

q

1

​

q

2

​

​

​

=

6.67×10

−11

×9.1×10

−31

×1.67×10

−27

9×10

9

×(1.6×10

−19

)×(1.6×10

−19

)

​

=

1

2.27×10

39

​

The ratio of Coulomb force to gravitational force for two protons is given as,

r

2

​

=

R

2

Gm

2

​

4πε

0

​

1

​

×

R

2

q

1

​

q

2

​

​

​

=

6.67×10

−11

×(1.67×10

−27

)

2

9×10

9

×(1.6×10

−19

)×(1.6×10

−19

)

​

=

1

1.24×10

36

​

(b)

The magnitude of Coulomb force between electron and proton is given as,

F=

4πε

0

​

1

​

×

R

2

q

1

​

q

2

​

​

=

(10

−10

)

2

9×10

9

×(1.6×10

−19

)×(1.6×10

−19

)

​

=2.304×10

−8

N

The acceleration of electron is given as,

a

1

​

=

m

1

​

F

​

=

9.1×10

−31

2.304×10

−8

​

=2.5×10

22

m/s

2

The acceleration of proton is given as,

a

2

​

=

m

2

​

F

​

=

1.67×10

−27

2.304×10

−8

​

=1.4×10

19

m/s

2

The enthalpy of combustion of 1 mole of acetylene for the reaction using the information in the table (attached as figure) is - 1,256 kJ/mol

The enthalpy of combustion of a substance is defined as the heat energy given out when one mole of a substance burns completely in oxygen.

Hence, The enthalpy of combustion of 1 mole of acetylene for the reaction using the information in the table is - 1,256 kJ/mol

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Mass of hydrate + crucible = 47.29 g

Mass of anhydrous salt = 2.7 g

Molar mass of anhydrous salt CuSO4 = 159.5 g

Given,

mass of empty crucible = 42.45 g

mass of hydrate salt= 4.84 g

mass of crucible after first heating = 46.1 g

mass of crucible after second heating= 45.153 g

mass of crucible after third heating= 45.15 g

so, as per the question we need to find...

Mass of hydrate + crucible = ? g

Mass of anhydrous salt = ? g

Molar mass of anhydrous salt CuSO4 = ? g

∴Mass of hydrate + crucible = 42.45 + 4.48 = 47.29 g

The given salt is in hydrate form, to remove water from this molecule we need to perform heating .

So we are taking the substance into the crucible as it is in less quantity.

Here, we performed heating 3 times and note the weight after every heating.

After this, assume that the water is totally evaporated and the remaining salt is in anhydrous form,

∴ Mass of anhydrous salt = 45.15 - 42.45 = 2.7 g

To find the molar mass of anhydrous salt of CuSO4,

atomic weight of Cu = 63.5 g

atomic weight of S = 32 g

atomic weight of O =16 g

∴ molar mass of anhydrous salt of CuSO4 = 63.5 + 32 + (16 ×3)

                                                                   =159.5 gm

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Answer:

1. Oxygen - 46.1%

2. Silicon - 28.2%

3. Aluminium - 8.23%

4. Iron - 5.63%

5. Calcium - 4.15%

6. Sodium - 2.36%

7. Magnesium - 2.33%

8. Potassium - 2.09%

9. Titanium - 0.565%

10.Hydrogen -0.140%

Explanation:

please mark me brainlist

[tex]\quad \huge \quad \quad \boxed{ \tt \:Answer }[/tex]

[tex]\qquad \tt \rightarrow \:2.8 × {10}^{-5}[/tex]

____________________________________

[tex] \large \tt Solution \: : [/tex]

[tex]\qquad \tt \rightarrow \: \dfrac{2.36 \times 10 {}^{ - 2} }{8.4 \times {10}^{2} } [/tex]

[tex]\qquad \tt \rightarrow \: \dfrac{2.36 }{8.4 } \times \cfrac{10 {}^{ - 2} }{10 {}^{2} } [/tex]

[tex]\qquad \tt \rightarrow \: 0.28 \times 10 {}^{ - 2 - 2} [/tex]

[tex]\qquad \tt \rightarrow \: 0.28 \times 10 {}^{ - 4} [/tex]

[tex]\qquad \tt \rightarrow \: 2.8 \times 10 {}^{ - 5} [/tex]

Answered by : ❝ AǫᴜᴀWɪᴢ ❞

Answer:

0

Explanation:

they cancel each other out (ex: 1 positive and 1 negative cancels, making it neutral or a charge of 0)

MgSo4 will be formed

Answer:

chemical reactions In our daily environment are

1) Cooking food

2) Photosynthesis

3) rusting

4) painting

5) respiration

6) combustion

7) Electrochemistry (including chemical batteries)

8)Digestion

9)Soap and detergent reactions

10)Acid-base reactions

11) fermentation

12) oxidation

13 ) burning of paper

14) riping of fruits

15) frying egg

16) souring of milk

17) baking

18) heating sugar

19) burning wood

20) rising bread

The earth's mantle will not change in the future because this region is safe from the intervention of human beings.

The transfer of heat and material in the mantle helps us to determine the landscape of Earth. Activity in the mantle moves the plate tectonics, that contributes to volcanoes, seafloor spreading, earthquakes, and building of mountains.

So we can conclude that the earth's mantle will not change in the future because this region is safe from the intervention of human beings.

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Answer:

Explanation:

The balanced equation for the decomposition of water is:

2H2O = 2H2 + 1O2

This tells us that we should expect 1 mole of O2 for every 2 moles of H2O, a molar ratio of (1 O2/2 H2O).

If we start with 2 moles of water, we should get (2mole H2O)*(1 O2/2 H2O) = 1 mole of H2.

But we are given just 20ml of water by the stingy boss.  We need to calculate the number of moles of water in that 20 ml.  We'll assume pure water at room temperature, so density = 1g/ml.  We have 20 g of H2O.  To find moles, divide by water's molar mass of 18 g/mole:

20g/(18g/mole) = 1.11 moles H2O

The moles of H2 produced would be:

(1.11 moles H2O)*(1 O2/2 H2O) = 0.55 moles O2 produced

We are not given the conditions of temperature and pressure, so the only way the calculate a volume of gas occupied by 1 mole of oxygen is to assume standard temperature and pressure (STP).  At STP 1 mole of gas occupies 22.4 liters.

1 mole of O2 will be 22.4 liters.

0.55 moles of O2 would be:

(0.55 mole O2)*(22.4 liters) = 12.32 liters

Answer:

alcohol

Explanation:

alcohol thus, C2H5OH

Considering the Charles's law, the sample of carbon dioxide gas will occupy 308.72 mL.

Charles's law establishes the relationship between the temperature and the volume of a gas when the pressure is constant. This law says that the volume is directly proportional to the temperature of the gas: for a given sum of gas at constant pressure, as the temperature increases, the volume of the gas increases and as the temperature decreases, the volume of the gas decreases.

Mathematically, Charles's law states that the ratio between volume and temperature will always have the same value:

[tex]\frac{V}{T} =k[/tex]

Considering an initial state 1 and a final state 2, it is fulfilled:

[tex]\frac{V1}{T1} =\frac{V2}{T2}[/tex]

In this case, you know:

Replacing in Charles's law:

[tex]\frac{250 mL}{298 K} =\frac{V2}{368 K}[/tex]

Solving:

[tex]V2=368 K\frac{250 mL}{298 K}[/tex]

V2= 308.72 mL

Finally, the sample of carbon dioxide gas will occupy 308.72 mL.

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Answer:

310mL

Explanation:

A sample of carbon dioxide gas occupies a volume of 250 mL at 25°C. What volume will it occupy at 95°C?

Use the formula:

V1

T1

=

V2

T2

Temperature conversion: __°C + 273 K

Answer:

Since Beryllium has a larger atomic radius than Sulphur its electrons are not strongly attracted to the nucleus hence lost easily. But Sulphur has a small atomic radius hence electrons are more closely attracted to the nucleus.

In the given heating curve, Particles of the substance have the most kinetic energy when the substance is (a) 1. A gas. The part of the graph that represents where the substance has the least amount of potential energy is labeled (b) 1. Solid.

The heating curve is the relationship between the heating system supply temperature and the outside air temperature.

Gas molecules have the highest average velocities among the three states of matter so gas has the highest kinetic energy.

During freezing, a substance loses a lot of potential energy so solid has the least potential energy.

Hence, In the given heating curve, Particles of the substance have the most kinetic energy when the substance is (a) 1. A gas.

The part of the graph that represents where the substance has the least amount of potential energy is labeled (b) 1. Solid.

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