c) A student titrated 50.0mL of a 0.10M solution of a certain weak acid with NaOH(aq) . The results are given in the graph above. (i) What is the approximate pKa of the acid?

Answer:

Explain:- 22.4L Imol Page 10 Many gas law problems involve calculating the volume of a gas produced by the reaction of volumes of other gases. The problem solving strategy that we have used throughout your chemistry course is still the same. 10.

The volume would 9.23 moles of oxygen gas occupy at 825 mmHg and 45 C 22.4L.

According to the Ideal Gas Law, all gases contain the same number of molecules at the same temperature, pressure, and volume (but not the same mass).

When the temperature and pressure are close to the point of transforming into a liquid or solid, the Ideal Gas law does not apply.

There are four governing assumptions for a gas to be "ideal": The volume of the gas particles is insignificant. The gas particles are all the same size and have no intermolecular forces with one another. According to Newton's Laws of Motion, the gas particles move at random.

Given :

Volume = ?

Number of moles = 9.23 moles

Temperature = 318K

Pressure = 825 mmHg = 1.08 atm

By an ideal gas equation

PV = nRT

V = nRT/ P

= 9.23 × 0.0821 × 318 /  1.08

= 22.4L

Thus, The volume would 9.23 moles of oxygen gas occupy at 825 mmHg and 45 C is 22.4L.

To learn more about an ideal gas law, follow the link;

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Answer:

B. People live longer than they used to

Explanation:

None of the other answers are correct.

Calculation: Molar mass of water = 180 % of water = > 180/286*100 = > 62.93%.

Answer: the percent by mass of water in the hydrate Na2CO3.10H20 is 62.93%.

Li2O

Fe(NO3)3

Al2O3

CuCl2

ZnSO4

All you have to do here is make sure your charges are balanced when you write the compound. For example, Iron (III) has a +3 charge, and nitrate has a -1 charge. You need 3 nitrates to match that charge, hence Fe(NO3)3.

Answer:

think I did this before and its V

Answer:

Matter

Explanation:

In classical physics and general chemistry, matter is any substance that has mass and takes up space by having volume.

Answer:

0.9moles of Zn are produced

Explanation:

Based on the reaction:

ZnO + 2Na → Na2O + Zn

1 mole of ZnO reacts with 2 moles of Na to produce 1 mole of Na2O and 1 mole of Zn

For 2 moles of sodium present, 1 mole of Zn is produced (The conversion factor is 2mol Na = 1mol Zn

If 1.8 moles of sodium are present:

1.8mol Na * (1mol Zn / 2mol Na) =

Answer:

C. Precipitation

It made me put more on my answer.

Answer:

A. Find a connection between variables

Explanation:

In the scientific method, the first step is to make an observation. To observe means to carefully monitor phenomena with a view to draw general patterns from specific occurrences.

The second step is to draw up a hypothesis; this is a tentative explanation for the observation.

The next step is to perform an experiment to determine the effect of change in one more variables on another variable. The experiment will confirm or disprove the hypothesis.

The last step is to draw a conclusion. In drawing up a conclusion, a scientist finally establishes the relationship between two variables and finds the connection between them.

Answer:

3Sn + 4HNO3 + H2O → 3H2SnO3 + 4NO

The empirical formula for dioxin (C₁₂H₄Cl₄O₂) is (C₆H₂Cl₂O).

We can determine the components of a chemical compound by looking at its formula. We can determine the precise number of atoms in a compound's molecule using its molecular formula. The ratio of these components is provided by the empirical formula. It is the compound's molecular formula scaled down to its lowest integer ratio.

Empirical formula for dioxin (C₁₂H₄Cl₄O₂) is (C₆H₂Cl₂O).

To determine the emperical formula:

Step1: Determine the masses.

Step 2: Multiply the grams by the atomic mass to get the number of moles.

Step 3: Subtract the least number of moles from the total number of moles of each element.

Learn more about the Emperical formula with the help of the given link:

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Explanation:

molar mass of the compound = 24 + 2× 14+ 16×6

= 24 + 28 + 96

= 148g/mol

no of moles = given mass / molar mass of the compound

1.4 = given mass/ 148

1.4×148=given mass

207.2 g

Answer: The final pressure is 116kPa or [tex]116kN/m^2[/tex]

Explanation:

The combined gas equation is,

[tex]\frac{P_1V_1}{T_1}=\frac{P_2V_2}{T_2}[/tex]

where,

[tex]P_1[/tex] = initial pressure of gas = [tex]250kN/m^2=250kPa[/tex]   [tex](1kN/m^2=1kPa)[/tex]

[tex]P_2[/tex] = final pressure of gas = ?

[tex]V_1[/tex] = initial volume of gas = v ml

[tex]V_2[/tex] = final volume of gas = [tex]1.8\times v=1.8vml[/tex]

[tex]T_1[/tex] = initial temperature of gas = [tex]75^0C=(75+273)K=348K[/tex]

[tex]T_2[/tex] = final temperature of gas = [tex]18^0C=(18+273)K=291K[/tex]

Now put all the given values in the above equation, we get:

[tex]\frac{250kPa\times v}{348}=\frac{P_2\times 1.8v}{291}[/tex]

[tex]P_2=116kPa[/tex]

The final pressure is 116kPa or [tex]116kN/m^2[/tex]

Answer: The rate increases 3 times on raising the temperature from 20degree to 30 degree​

Explanation:

According to Arrhenius equation with change in temperature, the formula is as follows.

[tex]ln \frac{k_{2}}{k_{1}} = \frac{-E_{a}}{R}[\frac{1}{T_{2}} - \frac{1}{T_{1}}][/tex]

where [tex]k_2[/tex] = rate constant at temp [tex]T_2[/tex]

[tex]k_1[/tex] = rate constant at temp [tex]T_1[/tex]

[tex]E_a[/tex]= activation energy

R= gas constant

[tex]T_1[/tex]= temperature = [tex]20^0C=(20+273)K=293K[/tex]

[tex]T_2[/tex]= temperature = [tex]30^0C=(30+273)K=303K[/tex]

[tex]ln \frac{k_{2}}{k_{1}} = \frac{-85\times 1000J/mol}{8.314J/Kmol}[\frac{1}{303} - \frac{1}{293}][/tex]

[tex]ln \frac{k_{2}}{k_{1}}=1.15[/tex]

[tex]\frac{k_{2}}{k_{1}}=3[/tex]

Thus rate increases 3 times on raising the temperature from 20degree to 30 degree​

Answer:The electron-domain geometry around this central atom is  linear

Explanation:

The hybridization is sp which means the number of electron pairs involved are 2. The electron domain geometry will have two sigma bonds and thus geometry will be linear.

The electron domain geometry will be Trigonal bipyramidal when hybridization is [tex]sp^3d[/tex]

The electron domain geometry will be octahedral when hybridization is [tex]sp^3d^2[/tex]

The electron domain geometry will be Trigonal planar when hybridization is [tex]sp^2[/tex]

The electron domain geometry will be tetrahedral when hybridization is [tex]sp^3[/tex]

Answer:

1.4 M

Explanation:

n(HBr)=3.115/81

so, 3.115/81=0.0385mol

according to the reaction, n(HBr)=n(KOH)=0.038 mol

C(KOH)=n/V=0.0385/0.02745

0.0385/0.02745 =1.4 M

in short the answer is 1.4 M (molarity)

Answer: The final pressure is 1600 torr.

Explanation:

To calculate the final pressure of the system, we use the equation given by Gay Lussac' Law. This law states that pressure of the gas is directly proportional to the temperature of the gas at constant volume.

Mathematically,

[tex]\frac{P_1}{T_1}=\frac{P_2}{T_2}[/tex]

where,

[tex]P_1\text{ and }T_1[/tex] are the initial pressure and temperature of the gas.

[tex]P_2\text{ and }T_2[/tex] are the final pressure and temperature of the gas.

We are given:

[tex]P_1=800.0torr\\T_1=27^oC=(27+273)K=300K\\P_2=?\\T_2=327^0C=(327+273)K=600K[/tex]

Putting values in above equation, we get:

[tex]\frac{800.0torr}{300K}=\frac{P_2}{600K}\\\\P_2=1600torr[/tex]

Thus the final pressure is 1600 torr.

Answer:

Explanation:

A: 0.8 KM/Min

1.6 x 30 = 48

48/60 = 0.8

Answer:

When magnesium burns in air, the oxygen in the air reacts with magnesium metal to produce magnesium oxide.

Magnesium burns in oxygen present in the air to produce magnesium.

Explanation:

c . produces bile is not the function of slaiva

Answer:

B. partially digests starch

Answer:  200mL

Explanation:

Answer:

? more info

Explanation:

Give users an example of the reactions you've learned about so we can have more of an idea. I'd be glad to help, if you edited your answer, meanwhile I too have homework in need of finishing.

Explanation:

This is cause of b) Static Electricity

It is also called Electrostatic force combined together.

Hope it helps ya :)

Areas where the air is warmed often have lower pressure because the warm air rises. These areas are called low pressure systems. Places where the air pressure is high, are called high pressure systems. A low pressure system has lower pressure at its center than the areas around it.

Answer:

There is no molecule or ion as ClO3. The correct formula of chlorate ion is ClO3-.

Answer: I believe that B) require target cell receptors to illicit a target cell response, is the right answer.

Explanation:

Solution :

According to the Graham's law of diffusion, we know that, the rate of the diffusion varies inversely to the molar mass of the gas, i.e.

Rate of diffusion, [tex]$r_d = \frac{a}{\sqrt M}$[/tex]

where, the 'M' is the molar mass of the gas.

Now in the case of the isotopes of the Krypton,

Atomic mass of [tex]$^{80}Kr$[/tex] = 80 AMU

Atomic mass of [tex]$^{82}Kr$[/tex] = 82 AMU

Atomic mass of [tex]$^{83}Kr$[/tex] = 83 AMU

So the ratio of the rate of diffusion of the three isotopes are :

[tex]$M_{d,^{80}Kr}:M_{d,^{82}Kr}:M_{d,^{83}Kr}$[/tex]

[tex]$=\frac{1}{\sqrt{80}}:\frac{1}{\sqrt{82}}:\frac{1}{\sqrt{83}}$[/tex]

[tex]$=0.1118:0.1104:0.10976$[/tex]

Dividing the above three with the smallest number among the three i.e. 0.10976, we get the relative rates of diffusion.

∴ [tex]$M_{d,^{80}Kr}:M_{d,^{82}Kr}:M_{d,^{83}Kr}$[/tex]

 = 1.02 : 1.01 : 1

Hence the relative rate of diffusion are :

[tex]$^{80}Kr(1.02)>^{82}Kr(1.01)>^{83}Kr(1.00)$[/tex]

Answer:

6.321 × 10^22

Explanation:

Mass of Oxygen =

3.36

g

Molar mass of oxygen (

O

2

) = 16 x 2 =

32

g

m

o

l

−

Total molecules in oxygen = Mass in grams/Molar mass x

N

A

=

3.36

32

x

6.02

x

10

23

=

6.321

x

10

22

Note:

N

A

(Avagadro's number) =

6.02

x

10

23

Hope it helps...

Answer: The molarity of given solution is 0.476 M.

Explanation:

Given : mass of sample (solute) = 7.0 g

Volume of solution (solvent) = 250 mL

Convert mL into L as follows.

[tex]1 mL = 0.001 L\\ 250 mL = 250 mL \times \frac{0.001 L}{1 mL}\\= 0.25 L[/tex]

Molar mass of NaCl is 58.44 g/mol. Hence, moles of NaCl are calculated as follows.

[tex]No. of moles = \frac{mass}{molar mass}\\= \frac{7.00 g}{58.44 g/mol}\\= 0.119 mol[/tex]

Molarity is the number of moles of a substance present in one liter of solution or solvent.

So, molarity of given solution is calculated as follows.

[tex]Molarity = \frac{no. of moles}{Volume (in L)}\\= \frac{0.119 mol}{0.25 L}\\= 0.476 M[/tex]

Thus, we can conclude that molarity of given solution is 0.476 M.