You have 0.21 moles of Al how many atoms do you have

Answer:

a. 137.93 dm3

b. 150.61 L

Answer:

C₈H₁₈

Explanation:

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: 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

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:

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:

I cant see it sorry

Explanation:

Answer:

Deandre is correct.

Explanation:

When shiny pennies turn dull, due to getting rust. It gets cover with a layer of black or brown color on its surface on the exposure of air.

In this problem,

Deandre says, "I think they turn dull because they're exposed to the air over time." Jamie says, "I think they turn dull because they get dirt on them from being dropped on the ground." Selina says, "I think there is dull metal inside the penny the entire time.

Out of three friends, Deandre is correct. Shiny pennies turn dull because they're exposed to the air over time.

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:

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: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:

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.

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:

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:

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

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

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.

Answer:

94.74 moles of NO₂ are produced.

Explanation:

Given data:

Volume of oxygen gas = 3714 L

Temperature = 273 K

Pressure = 1 atm

Moles of NO₂ produced = ?

Solution:

Chemical equation:

4NH₃  + 7O₂   →      4NO₂ + 6H₂O

Number of moles of oxygen:

At STP one mole of any gas occupy 22.4 L volume. Thus, 3714 L gas contain,

3714 L× 1  mol / 22.4 L

165.8 mol

now we will compare the moles of oxygen and nitrogen dioxide.

                    O₂         :        NO₂

                     7           :          4

                   165.8      :        4/7×165.8 = 94.74 mol

Thus, 94.74 moles of NO₂ are produced.

Answer:

umm probly glucose and oxygen.??

Explanation:

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 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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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 equilibrium concentration  of N₂ : 1.992

Given

Kc = 6.0 x 10⁻² at 500°C

0.253 M H₂ and 0.044 M NH₃

Reaction

3H₂(g) + N₂(g) = 2NH₃(g)

Required

The equilibrium concentration  of N₂

Solution

Kc for the reaction :

[tex]\tt Kc=\dfrac{[NH_3]^2}{[H_2]^3[N_2]}\\\\0.06=\dfrac{0.044^2}{0.253^3\times [N_2]}\\\\(N_2]=1.992[/tex]

Answer:

Veins

Explanation:

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

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:

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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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:

8.92 m/s

Explanation:

Distance covered = 107 m

Time = 12 s

Average speed = ?

The relationship between the parameters is given by;

Average speed = Distance covered / Time

Average speed = 107 / 12

Average speed = 8.92 m/s