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2 years ago

Composition of the nuclei of two atomic species A and B are given below:

Chemistry

1 answer:

Inessa [10]2 years ago

5 0

Explanation:

(a) mass number = atomic number + number of neutrons

(the atomic number is the number of protons of an element)

mass number of A = 11 + 12 = 23

mass number of B = 17 + 18 = 35

(b) +1 and -1, respectively

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Acetic acid (HC2H3O2, Ka=1.8x10^-5) is a weak acid. Calculate the pH of an aqueous solution of .25M acetic acid.

tensa zangetsu [6.8K]

Answer: The pH of an aqueous solution of .25M acetic acid is 2.7

Explanation:

$HC_2H_3O_2\rightarrow H^+C_2H_3O_2^-$

cM 0 0

$c-c\alpha$ $c\alpha$ $c\alpha$

So dissociation constant will be:

$K_a=\frac{(c\alpha)^{2}}{c-c\alpha}$

Give c= 0.25 M and $\alpha$ = ?

$K_a=1.8\times 10^{-5}$

Putting in the values we get:

$1.8\times 10^{-5}=\frac{(0.25\times \alpha)^2}{(0.25-0.25\times \alpha)}$

$(\alpha)=0.0084$

$[H^+]=c\times \alpha$

$[H^+]=0.25\times 0.0084=0.0021$

Also $pH=-log[H^+]$

$pH=-log[0.0021]=2.7$

Thus pH is 2.7

5 0

3 years ago

Why do scientist study volcanos!!

agasfer [191]

Answer:

Volcanologists use many different kinds of tools including instruments that detect and record earthquakes (seismometers and seimographs), instruments that measure ground deformation (EDM, Leveling, GPS, tilt), instruments that detect and measure volcanic gases (COSPEC), instruments that determine how much lava is moving underground (VLF, EM-31), video and still cameras, infrared cameras, satellite imagers, webcams, etc!

Explanation:

I HOPE IT HELPED

6 0

2 years ago

2H2 + O2 --> 2H2O can be classified as what type of reaction?

Sveta_85 [38]

Combustion reaction
Key: O2
O2 is normally in a chemical formula when you are used to burn anything, so basically, anything with O2 involves burning.

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2 years ago

Read 2 more answers

How does the law of conservation of mass relate to the number of atoms of each element that are present before a reaction vs. th

TiliK225 [7]

The law of conservation of mass or principle of mass conservation states that for any system closed to all transfers of matter and energy, the mass of the system must remain constant over time, as system's mass cannot change, so quantity cannot be added nor removed. Hence, the quantity of mass is conserved over time.

The law implies that mass can neither be created nor destroyed, although it may be rearranged in space, or the entities associated with it may be changed in form. For example, in chemical reactions, the mass of the chemical components before the reaction is equal to the mass of the components after the reaction. Thus, during any chemical reaction and low-energy thermodynamic processes in an isolated system, the total mass of the reactants, or starting materials, must be equal to the mass of the products.

According to the Law of Conservation, all atoms of the reactant(s) must equal the atoms of the product(s).
As a result, we need to balance chemical equations. We do this by adding in coefficients to the reactants and/or products. The compound(s) itself/themselves DOES NOT CHANGE.

6 0

2 years ago

Cuánto es aproximadamente 29, 029 pies en millas

dolphi86 [110]

Seria 5.498 millas

Solo se debe dividir el valor de longitud entre 5280

6 0

1 year ago