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4 years ago

9

Oxidation can be defined as_______ question 4 options: increase in oxidation number decrease in oxidation number gain of electro

n non of the above

1 answer:

KiRa [710]4 years ago

8 0

If you combine zinc with apple juice it is toxic.

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a certain metal hydroxide, m(oh)2, contains 32.8% oxygen by mass. what is the identity of the metal m?

Leno4ka [110]

Total mass = x

It would be: x*32.38/100 = 32

x = 3200/32.38 = 97.56

Atomic mass of (OH)2 = 34

So, remaining mass = 97.56-34 = 63.56

which is approximately equal to mass of copper

So, we can say m is copper here, and formula of the compound would be Cu(OH)2

4 0

3 years ago

The potential energy diagram for a reaction starts at 380 kJ and ends at 100 kJ. What type of reaction does the diagram best rep

ohaa [14]

Answer: A. Exothermic reaction

Explanation: Enthalpy change for a reaction is sum of enthalpy of formation of products minus sum of enthalpy of formation of reactants.

When the energy level of reactants is above as compared to the products, the reaction is exothermic and when its opposite then reaction is endothermic.

From given information, the potential energy diagram starts at 380 kJ means the energy level of reactants is 380 kJ. It ends at 100 kJ means the energy of products is 100 kJ.

Enthalpy of reaction = 100 kJ - 380 kJ

Enthalpy of reaction = -280 kJ

Negative sign of enthalpy change indicates an Exothermic reaction.

5 0

3 years ago

Read 2 more answers

Polonium- 210 , Po210 , decays to lead- 206 , Pb206 , by alpha emission according to the equation Po84210⟶Pb82206+He24 If the ha

elixir [45]

Answer:

0.269 g

Explanation:

$Po_{210} ^{84}$ ⟶ $Pb_{206} ^{82}$ + $+ He_{4} ^{2}$

Data:

Half-life of $Po_{210} ^{84}$ (T(1/2)) = 138.4 days

Mass of PoCl4 = 561 mg (0,561 g) and molecular weight of PoCl4 = 350. 79 g/mol

Time = 338.8 days

Isotopic masses

$Po_{210} ^{84}$ = 209.98 g/mol

$Pb_{206} ^{82}$ = 205.97 g/mol

Concepts

Avogadro’s number: This is the number of constituent particles that are contained in a mol of any substance. These constituted particles can be atoms, molecules or ions). Its value is 6.023*10^23.

The radioactive decay law is

N=Noe^(-λt)

Where:

No = number of atoms in t=0

N = number of atoms in t=t (now) in this case t=338.8 days

λ= radioactive decay constant

The radioactive constant is related to the half-life by the next equation

λ= $\frac{ln 2}{t(1/2)}$

so

λ= $\frac{ln2}{138.4 days}$ =0,005008 days^(-1)

No (Atoms of $Po_{210} ^{84}$ in t=0)

To get No we need to calculate the number of atoms of $Po_{210} ^{84}$ in the initial sample. We have a sample of 0,561 g of PoCl4. If we get the number of moles of PoCl4 in the sample, this will be the number of moles of $Po_{210} ^{84}$ in the initial sample.

This is:

$\frac{0,561 g of PoCl4}{350. 79 g of PoCl4 /mol}$ = 0,001599 mol of PoCl4

This is the number of mol of $Po_{210} ^{84}$ in the initial sample.

To get the number of atoms in the initial sample we use the Avogadro’s number = 6.023*10^23

0,001599 mol of $Po_{210} ^{84}$ * 6.023*10^23 atoms/ mol of $Po_{210} ^{84}$ = 9.632 *10^20 atoms of $Po_{210} ^{84}$

Atoms after 338.8 days

We use the radioactive decay law to get this value

N=Noe^(-λt)

N=9.632*10^20 e^(-0,005008 days^(-1) * 338.8 days) =1.765*10^20

This is the number of atoms of $Po_{210} ^{84}$ in the sample after 338.8 days has passed

The number of atoms $Po_{210} ^{84}$ transformed is equal to the number of atoms of $Pb_{206} ^{82}$ produced.

The number of atoms of $Po_{210} ^{84}$ transformed is No - N

9.632 *10^20 – 1.765 *10^20 = 7.866*10^20

So, 7.866*10^20 is the number of atoms of $Pb_{206} ^{82}$ produced

We can get the mass with the Avogadro’s number

(7.866*10^20 atoms of $Pb_{206} ^{82}$ ) / ( 6.023*10^23 atoms of $Pb_{206} ^{82}$ / mol of $Pb_{206} ^{82}$ = 0.001306 moles of $Pb_{206} ^{82}$

This number of moles have a mass of:

(0,001306 moles of $Pb_{206} ^{82}$ )* (205.97 g of $Pb_{206} ^{82}$ /mol of $Pb_{206} ^{82}$ ) = 0.269 g

3 0

3 years ago

How does intertia affect gymnastics

Olegator [25]

Inertia is resistance to changes in motion. Which means if you are at rest it takes an external force to get you moving. And once you are moving it takes an external force to change the direction of that motion.

<span>For a person doing gymnastics the point that is subject to the above statement is her center of mass (roughly her belly button) . </span>

<span>So for example, once you launch into the air, gravity is the only significant force on you. It keeps you from traveling out into space by pulling you down and the trajectory of your belly button is a parabola. Now there is nothing you can do with your muscles (internal forces) to change that trajectory, even though you can do twists & turns about the center of mass. The height and range of the parabolic trajectory is determined by the angle & speed at which you initially launch yourself.
_____________________________________________________________
</span><span>inertia is one of newtons laws of motion so an object in motion tends to remain in motion until another force acts upon it that is what newton said when you are doing a back hand spring it is easier to keep going then to stop
</span><span>_____________________________________________________________

Hope this helps!!! :D
I love gymnastics!!!!</span>

6 0

3 years ago

What is the amount of aluminum chloride produced from 40 moles of chlorine and excess aluminum?

Vera_Pavlovna [14]

Answer: Molar mass of Al = 26.98 g/mol

mass of Al = 12 g

mol of Al = (mass)/(molar mass)

= 12/26.98

= 0.4448 mol

According to balanced equation

mol of AlCl3 formed = moles of Al

= 0.4448 mol

Answer: 0.445 mol

hope this help boo❤️❤️❤️

Explanation:

3 0

3 years ago