You have 4.72x10^25 atoms of a substance with MW of 136.94 g/mol How many moles do you have

Answer:

2 C Atoms

Explanation:

When you have coefficient of 2 next to a compound element, it indicates there are 2 of each compound element. In the compound element, there is one C Atom, and 2×1 is 2.

a. 1,4332 g

b. 7.54~g

Given

Reaction

MgCl2 (s) + 2 AgNO3 (aq) → Mg(NO3)2 (aq) + 2 AgCl (s)

20 cm of 2.5 mol/dm^3 of MgCl2

20 cm of 2.5 g/dm^3 of MgCl2

Required

the mass of silver chloride - AgCl

Solution

a. mol MgCl2 :

[tex]\tt 20~cm^3=20\times 10^{-3}~dm^3\\\\mol=M\times V\\\\mol=2.5~mol/dm^3\times 20\times 10^{-3}DM^3=0.05[/tex]

From equation, mol AgCl = 2 x mol MgCl2=2 x 0.05=0.1

mass AgCl(MW=143,32 g/mol)= 0.1 x 143,32=1,4332 g

b. mol MgCl2 (MW=95.211 /mol):

[tex]\tt mol=M\times V\\\\mol=\dfrac{2.5~g/dm^3}{95,211 g/mol}=0.0263~mol/dm^3[/tex]

From equation, mol AgCl = 2 x mol MgCl2=2 x 0.0263=0.0526

mass AgCl(MW=143,32 g/mol)= 0.0526 x 143,32=7.54~g

Answer:

a. 137.93 dm3

b. 150.61 L

Answer:

C₈H₁₈

Explanation:

ANSWER

An atom of element is electrically neutral because the number of positive protons are equal to number of negative electrons.

Answer:

Although thomson model of atom explained that atoms are electrically neutral, the results of this experiment carried by other scientists couldnot be explained by this model

422600000 or 4,226x 10^8

Answer:

422.6*10^6

Explanation:

(4.2*10^8)+(2.6*10^6)

4.2*10^8+2.6+10^6

(4.2*10^2+2.6)*10^6

(4.2*100+2.6)*10^6

(420+2.6)+10^6

Final Answer:

422.6*10^6

Answer:

Your answer should be D

Explanation:

I think the answer is metric system of units

because it is the most widely used system of units and its use in both science and business.

Answer:

The description of that same scenario is listed mostly in the explanation portion following.  

Explanation:

This same respiratory system involves several lungs, as well as the systemic circulation concerning this same human heart, which operates in conjunction to pick up more oxygen as well as expel CO2 from the body.

Answer:

The three possible structures for octane, C8H18 and give their IUPAC names are -

(structures are attached)

The octane is a hydrocarbon with 8 carbon atoms and 18 hydrogen atoms. The molecular formula of octane is C8H18.

The three possible structures for octane, C8H18 and give their IUPAC names are -

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169.71 minutes

Given

Rate of diffused of Hydrogen=5 gm/30 min

Required

The time required for SO₂

Solution

Graham's law: the rate of effusion of a gas is inversely proportional to the square root of its molar masses or  

the effusion rates of two gases = the square root of the inverse of their molar masses:  

[tex]\tt \dfrac{r_1}{r_2}=\sqrt{\dfrac{M_2}{M_1} }[/tex]

r₁=5gm/30 min

M₁=molar weight of H₂-hydrogen= 2 g/mol

M₂=molar weight of SO₂-sulfur dioxide= 64 g/mol

[tex]\tt \dfrac{5/30}{r_2}=\sqrt{\dfrac{64}{2} }\\\\\dfrac{5/30}{r_2}=4\sqrt{2}\\\\\dfrac{5}{30}=r_2.4\sqrt{2}\\\\r_2=\dfrac{5}{30\times 4\sqrt{2} }=\dfrac{\sqrt{2} }{48}[/tex]

the time required (for the same amount=5 gm) :

[tex]\tt \dfrac{5}{x}=\dfrac{\sqrt{2} }{48}\rightarrow x=120\sqrt{2}=169.71 minute[/tex]

Answer:

44° to 45°

Explanation:

The altitude of Polaris star  when viewed from New York City is somewhat between 44° to 45°. However, Polaris is directly overhead at the North Pole (90° of latitude); in other words, the angle between Polaris and the horizon at the North Pole is 90°. This angle is called "the altitude" of Polaris.

Answer:Hotter objects have a higher average kinetic energy and a higher temperature ; cooler objects have a lower average kinetic energy and a lower temperature.

Explanation:

Answer:

D. Carbon​.

Explanation:

Carbon can be mixed with Many things. for example, YOU are mostly made out of carbon. Other things include furniture, clothing, plastics, charcoal, pencil led, diamonds, and gas.

Answer:

b                                 xplanation:

Answer:

Ag⁺(aq) + Cl⁻(aq)       →      AgCl(s)  

Explanation:

Chemical equation:

AgNO₃(aq) + NaCl(aq)       →     AgCl(s) + NaNO₃(aq)

Balance chemical equation:

AgNO₃(aq) + NaCl(aq)       →     AgCl(s) + NaNO₃(aq)

Ionic equation

Ag⁺(aq)+ NO₃⁻(aq) + Na⁺(aq)+ Cl⁻(aq)       →      AgCl(s)  + Na⁺(aq)+ NO₃⁻(aq)

Net ionic equation:

Ag⁺(aq) + Cl⁻(aq)       →      AgCl(s)  

The NO₃⁻((aq) and Na⁺ (aq) are spectator ions that's why these are not written in net ionic equation. The AgCl can not be splitted into ions because it is present in solid form.

Spectator ions:

These ions are same in both side of chemical reaction. These ions are cancel out. Their presence can not effect the equilibrium of reaction that's why these ions are omitted in net ionic equation.  

Answer:

Explanation:

Given parameters:

Mass of water  = 40g

Initial temperature  = 33°C

Final temperature  = 23°C

Specific heat capacity of water  = 4.2J/g°C

Unknown:

Quantity of heat = ?

Solution:

To solve this problem, we use the expression below;

       H  = m c Δt

H is the quantity of heat

m is the mass

c is the specific heat capacity

Δt is the change in temperature

      H  = 40 x 4.2 x (23 - 33) = -1680J

The water will have to lose 1680J of heat to bring it to that final temperature.

Answer: Helium

Explanation: Beryllium (Be) has an electron configuration of 2-2. Losing two electrons will leave it with two electrons in the first shell, resembling Helium.

Answer:

I cant see it sorry

Explanation:

Answer:

umm probly glucose and oxygen.??

Explanation:

Answer:

The greater the ionization energy, the more difficult it is to remove an electron. The ionization energy may be an indicator of the reactivity of an element. Elements with a low ionization energy tend to be reducing agents and form cations, which in turn combine with anions to form salts.

Answer:

1. Polar

2. Non-polar

3. Non-polar

4. Polar

5. Non-polar

6. Polar

Explanation:

Polar bonds are formed between molecules that share electrons unequally/unevenly. In a polar molecule, one atom is more electronegative than the other i.e it attracts/pulls more electrons than the other atom, hence, it ends up leaving the other atom with a positive charge i.e fewer electrons around its atom. Also, every molecule that has a symmetrical arrangement is NON-POLAR while the opposite is POLAR.

Based on this, the answers to the asked questions are in BOLD.

1. A POLAR bond is one where there are more shared electrons grouped around one atom than the other.

2. A NON-POLAR bond is one where the electrons are evenly distributed between the two atoms sharing electrons.

3. A molecule with symmetry is NON-POLAR

4. A molecule that does not have symmetry is POLAR.

5. A NON-POLAR molecule has its valence electrons evenly distributed around the molecule.

6. A POLAR molecule has one of its sides with more or fewer electrons than the other sides.

Answer:

A ground wire helps those positive charges get to the ground in a safe, direct and controlled way, where they can be discharged without the risk of electrical shock or fire. Shock Absorber Excess electrical charges are common in any home.

Explanation:

:3

Answer: The percent composition of oxygen is 54.5%

Explanation:

Below I have attached my work through, but essentially the percent composition relies on finding the mass of the oxygens and dividing it by the mass of the whole compound. The masses of the elements can be found on the periodic table and added together to get a mass of the whole compound- ascorbic acid. Then, you turn this proportion into a percent by multiplying by 100%.

Answer:

54.5% is the correct answer

Answer:

One element takes the place of another in a compound

Explanation:

a p e x - just did the test

The statement best describes a single-replacement reaction as one element takes the place of another in a compound. The correct option is A.

A single replacement reaction is one in which when the reaction happens, one element is substituted by another in a compound. It is also called displacement reaction. The replacing material will always be a pure element.

An example is Zn + 2HCl -> ZnCl₂ + H₂

Thus, the correct option is A. one element takes the place of another in a compound.

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#SPJ2

Answer:

Veins

Explanation:

Veins, which usually look blue, return blood to the heart.

Answer:

The dirty dozen.

Explanation:

This is mainly seen in the control of hazardous waste and its regulations through treaty in the control of persistent organic pollutant(POPs). This regulation is seen to occur in 12 widely used persistent organic pollutants; these are seen to have the ability to absorb and store tissues that make them fatty especially in humans and also animals found in the higher trophic levels or in the food web. That being said, it can be noted that the dirty dozen can move or even attain hundreds, or thousands of levels towards the environ and also in other cases, transporting them through air or water as the case may be.

The theoretical yield of the reaction : 151.64 g

The limiting reactant :  N₂

The excess reactant : H₂

Reaction

N₂+3H₂⇒2NH₃

A method that can be used to find limiting reactants is to divide the number of moles of known substances by their respective coefficients(mol ratio), and the smaller become a limiting reactant

mass of N₂=125 g

mol N₂(MW=28 g/mol) :

[tex]\tt mol=\dfrac{mass}{MW}\\\\mol=\dfrac{125}{28}=4.46[/tex]

mass H₂ = 125 g

mol H₂(MW= 2 g/mol) :

[tex]\tt mol=\dfrac{125}{2}=62.5[/tex]

From the equation, mol ratio N₂ : H₂ = 1 : 3

Limiting reactant : N₂ : H₂ =

[tex]\tt \dfrac{4.46}{1}\div \dfrac{62.5}{3}=4.46\div 20.8[/tex]

N₂  : limiting reactant

H₂ : excess reactant

mol NH₃ based on limiting(N₂) (from equation N₂ : NH₃ = 1 : 2)

[tex]\tt mol~NH_3=\dfrac{2}{1}\times 4.46=8.92[/tex]

mass NH₃ (MW=17 g/mol) :

[tex]\tt mass=mol\times MW\\\\mass=8.92\times 17=151.64[/tex]

Answer:

180,000 ants

Explanation:

For this problem we can create the following simple formula to solve this problem...

f(x) = 6x

where the variable x represents the number of ants that a single Anteater needs to eat per day. After a quick online search we can see that a single Anteater eats roughly 30,000 ants per day. If we use this value and plug it into the simple formula we can get the total number of ants 6 anteaters need to eat to survive.

f(x) = 6 * 30,000

f(x) = 180,000

Answer:

D.When the boiling points of the components are different

Explanation:

I believe the formal name for this procedure is actually distillation.