contribution of chemistry in medicines​

Answer:

Neutrons play no role in the net charge of an atom, so you can ignore them here.

Proton = 7

Electron = 10

Net Charge = 7 - 10

= -3

Again,

Proton = 3

Electron = 2

Net Charge = 3 - 2

= 1

From the calculations, we can see that the pH of the solution is 2.3

The term Kb is know as the base dissociation constant. It gives the extent to which a base dissociates in solution.

Hence;

Ka = Kw/Kb = 1 * 10^-14/ 9.88 x 10-8 = 1 * 10^ -7

We have to set up the ICE table;

       NH4^+(aq) + H2O(l)⇔ H3O^+(aq) + NH3(aq)

I        2.55                               0                   0

C        -X                                  +X                 +X

E       2.55 - x                            x                   x

Ka = [H3O^+] [NH3]/[NH4^+]

1 * 10^ -7 = x^2/2.55 - x

1 * 10^ -7 (2.55 - x) = x^2

x^2 - 2.55 * 10^ -7 + 1 * 10^ -7x = 0

x=0.0005 M

So;  [H3O^+] = [NH3] = 0.0005 M

pH = -log(0.0005 M) = 2.3

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Taking into account the definition of avogadro's number, in 7.54×10¹⁰ moles of water are 4.54×10³⁴ molecules of water.

Avogadro's Number or Avogadro's Constant is called the number of particles that make up a substance (usually atoms or molecules) and that can be found in the amount of one mole of said substance. Its value is 6.023×10²³ particles per mole. Avogadro's number applies to any substance.

You can apply the following rule of three: if 6.023×10²³ molecules are contained in 1 mole of water, then 4.54×10³⁴ molecules are contained in how many moles of water?

amount of moles of water= (4.54×10³⁴ molecules × 1 mole)÷ 6.023×10²³ molecules

amount of moles of water= 7.54×10¹⁰ moles

Finally, in 7.54×10¹⁰ moles of water are 4.54×10³⁴ molecules of water.

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Answer:

D. Mixed doubles tennis

Explanation:

Mixed doubles tennis is just normal tennis but the 'mixed' means that on both teams there is both one man and one woman.

Answer:

-trees

-solar energy

-hydroelectricity

-wind energy

sorry I can only think or 4 atm

Answer:

the particles of matter are arranged in different ways for the different states

Explanation:

because solid liquid and gas all three matters have different states for example the particles in a solid are closely packEd and form of movement is vibration

Answer:

volume = 1.04 dm^3

Explanation:

Data:

volume = ?

Molarity, M = 0.25M

mass = 28.5g

Molar mass = 110.25g

Moles = ?

Solution:

First find number of moles,

 moles = mass in gram / molar mass

             = 28.5 / 110.25

              = 0.258

              ≈ 0.26 moles

Now,

          Molarity = [tex]\frac{no. of moles}{volume in dm^3}[/tex]

So,

           Volume in dm^3 = [tex]\frac{no. of moles}{molarity}[/tex]

                                       =  0.26 / 0.25

                         Volume  = 1.04 dm^3

Chemical weathering is caused by rain water reacting with the mineral grains in rocks to form new minerals (clays) and soluble salts.

Chemical weathering changes the molecular structure of rocks and soil.

Chemical Weathering is defined as the chemical reaction that takes place between the rain, flowing water, and rocks along with minerals.

It results in the decaying of minerals and the rocks for the formation of new minerals, as we as, the soluble salts due to the reaction being highly acidic.

Since the reaction is acidic, it causes 'unrecognizable facial features on a marble statue.

These reactions occur particularly when the water is slightly acidic.

Thus, chemical weathering is caused by rainwater reacting with the mineral grains in rocks to form new minerals (clays) and soluble salts.

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Answer:

= 0.524M

Explanation:

data;

volume = 490ml

              = 490 / 1000

               = 0.49 dm^3

moles = 0.257 moles

molarity = ?

solution:

molarity = [tex]\frac{no. of moles}{volume in dm^3}[/tex]

               = 0.257 / 0.49

 molarity  = 0.524M

Answer:According to the Aufbau principle, the electrons fill the 4s sublevel before beginning to fill the 3d sublevel. However, the outermost s electrons are always the first to be removed in the process of forming transition metal cations.

Explanation:hope its help

Answer:

electrical

Explanation:

because since electricity moves thus giving us kinetic energy and it also stores energy giving is potential energy

From the calculations, the equilibrium constant of the reverse reaction is 2.22 * 10^3.

The term equilibrium constant refers to a number that shows the extent to which reactants are converted into products.

We can see that the equation is COCI₂(g) CO(g) + Cl₂(g) having Kc = 0.00045. The equilibrium constant of the reverse reaction is; 1/0.00045 = 2.22 * 10^3.

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Answer:

1. Cadmium sulfide

2. Iron (III) hrydroxide

3. Barium carbonate

Cadmium sulfide, iron hydroxide, and barium carbonate will form a precipitate.

The precipitation reaction can be described as a chemical reaction taking place in an aqueous solution where two ionic bonds combine in order to form an insoluble salt.

These insoluble salts form are called precipitates in precipitation reactions. Precipitation reactions are commonly double displacement reactions in which the production of a solid forms a residue known as the precipitate.

The first reaction:  [tex]Na_2S + Cd(NO_3)_2 \longrightarrow CdS + 2NaNO_3[/tex]

The cadmium sulfide forms precipitates in this reaction.

The second reaction: [tex]FeCl_3 + 3KOH \longrightarrow 3KCl + Fe(OH)_3[/tex]

The iron hydroxide forms precipitate in this reaction.

The third reaction:[tex]Na_2CO_3 + Ba(NO_3)_2 \longrightarrow BaCO_3 + 2NaNO_3[/tex]

The barium carbonate forms precipitate in this reaction.

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Answer:

AU(s)| AU³||CL,Cl2|Pt(s)

Explanation:

I started with the anode on my left hand side because AU id undergoing oxidation and on the right hand side CL is undergoing reduction hence it's a cathode, and since for the cathode we don't have a metal in a solid state we are going to add Pt

Answer:

Compact cars with smaller engines can't achieve more than 30 mpg because of the weight difference

Hope This Helped

Answer:

c

Explanation:

Science is best described as a way of building knowledge about the world around us through observation and experimentation.

Answer:

network

Explanation:

ionic is strongest

chegg

A network is the type of solid that has the weakest forces holding it together.

A network, in computing, is a group of two or extra gadgets or nodes that could talk. The gadgets or nodes in question can be connected through physical or wi-fi connections. The key is that there are at least separate components, and they may be connected.

A home wireless LAN (wireless local area network, or Wi-Fi network) is a good example of a small client-server network. Various devices in the home are wirelessly connected to a router that acts as the central node (server) in the home.

A network is a collection of computers, servers, mainframes, community gadgets, peripherals, or other devices related to permitting facts sharing. An example of a network is the net, which connects hundreds of thousands of people everywhere in the global.

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0.22 moles

Moles are a measurement used in chemistry that describes the amount of an atom based on the number of atoms. One mole is equal to [tex]6.022*10^{23}[/tex], which is the number of atoms in 12 grams in Carbon-12.

Mass of Copper

Before finding the moles of copper, we need to know the mass. We are told that a door handle is 140g, but only 10% is copper.

To find 10% for 140 we can multiply 140 * 0.1.

This means there are 14 grams of copper.

Moles of Copper

Now, we can use dimensional analysis to convert grams to moles. To do this we need to know how many grams of copper are in 1 mole. This number is called the molecular mass and can be found on the periodic table. This number is usually directly below the element's symbol and is the only number with decimal points (not all periodic tables will have the exact same molecular mass because the number can change, but they will be close).

The molecular mass for copper is 63.55. Next, we can set up a dimensional analysis conversion. Dimensional analysis is when you multiply some value by a ratio of 2 different values with 2 different units. This may sound confusing but it makes more sense when you do it.

When setting up an expression like this, make sure that the units cancel out so you are only left with the one you want. Units will cancel out if one is in the numerator of a ratio and the other is in the denominator.

Next, multiply this out (which is equivalent to dividing 14/63.55)

So, when rounded to significant figures, there are 0.22 moles in 14 grams of copper.

Answer:

Limiting reactant

Explanation:

In a chemical reaction is the substance that is totally consumed when the chemical reaction is complete.

Answer:

I don't know

Explanation:

I don't know the answer but it is use for car

Answer:

0.956 grams O₂        or
0.956 milliliters O₂   or
9.56 x 10⁻⁴ L O₂

Explanation:

If the reactant were to decompose completely, the entire balanced reaction would look like this:

2 KClO₃ --> 2 K(s) + Cl₂(g) + 3 O₂(g)

To find the answer, (1) convert the grams of KClO₃ to moles (via molar mass from periodic table), then (2) convert moles KClO₃ to moles O₂ (via mole-to-mole ratio from balanced equation), then (3) convert moles O₂ to grams (via molar mass from periodic table).

Molar Mass (KClO₃) = 39.098 g/mol + 35.453 g/mol + 3(15.999) g/mol

Molar Mass (KClO₃) = 122.548 g/mol

Molar Mass (O₂) = 2(15.999) g/mol

Molar Mass (O₂) = 31.998 g/mol

2.44 g KClO₃           1 mole KClO₃             3 moles O₂             31.998 g
--------------------  x  --------------------------  x  --------------------  x  ------------------------
                                   122.548 g             2 moles KClO₃        1 mole O₂

= 0.956 grams O₂
= 0.956 milliliters O₂
= 9.56 x 10⁻⁴ L O₂

**The prompt askes to determine the volume. As far as I know, there is no easy way to find liters/milliliters with the given information. As such, I found the mass of O₂ instead. Technically, grams is equal to milliliters, so this may be what you are looking for. Then, you can convert from milliliters to liters by dividing by 1,000 (if necessary). **

A student weighs out 51.57 grams of sodium permanganate. The moles of  sodium permanganate is 0.363 mol.

Molar mass of many compounds can be calculated by dividing the mass of the compound by the number of moles of the compound.

The molar mass is given 141.93 g/mol.

To calculate the moles

[tex]\rm Number\;of \;moles= \dfrac{mass}{molar\;mass}\\\rm Number\;of \;moles= \dfrac{51.57}{141.93} = 0.363\;mol[/tex]

Thus, the moles are 0.363 mol.

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Answer:

45.13 psi

Explanation:

Assuming the volume does not change

P1/T1 = P2/T2         T  must be in Kelvin

40/(273.15) = P2/(273.15 + 35)       P2 = 45.13 psi

Answer:

Both acids and bases are electrolytes which means that they're good conductors of electricity. Acids and bases both produce ions in water solution. Acids release hydrogen ions (H+) whereas Bases release hydroxide ions (OH-). The process of mixing acid or a base in water is an exothermic one.

Answer:

Electrolytes

Explanation:

Both acids and bases are electrolytes which means that they're good conductors of electricity. Acids and bases both produce ions in water solutions. Acids release hydrogen ions (H+) whereas Bases release hydroxide ions (OH-). The process of mixing acid or a base in water is an exothermic one.

Answer:

Your answer is B, Electrochemistry!

Explanation:

This is the part of chemistry that studies the chemical process in which electrons flow. This flow is called electricity. Electricity is generated by the flow of electrons, from one element to another element. This reaction is called oxidation reduction.

Answer: B

Explanation:

Answer:

= 0.366 M

Explanation:

data;

moles = 0.381 moles

volume = 1039ml

             = 1039 / 1000

             = 1.039dm^3

molarity = ?

solution

         molarity = [tex]\frac{moles}{volume in dm^3}[/tex]

                        = 0.381 / 1.039

         molarity = 0.366 M

Answer: The high temperature raises the volume of air inside the ball according to Charles's law because this law describes how a gas will behave at constant pressure.

Answer:

D. The high temperature raises the volume of air inside the ball according to Charles's law because this law describes how a gas will behave at constant pressure.

Explanation:

I took the exam