Help, due tonight (2/19/2021) at 11:59pm!

Answer:

1.5055×10²⁴ molecules

Explanation:

From the question given above, the following data were obtained:

Number of mole CO₂ = 2.5 moles

Number of molecules CO₂ =?

The number of molecules present in 2.5 moles CO₂ can be obtained as:

From Avogadro's hypothesis,

1 mole of CO₂ = 6.022×10²³ molecules

Therefore,

2.5 mole of CO₂ = 2.5 × 6.022×10²³

2.5 mole of CO₂ = 1.5055×10²⁴ molecules

Thus, 1.5055×10²⁴ molecules are present in 2.5 moles CO₂

Answer:

c. when the meniscus is between marks, estimate the reading to the nearest tenth of a division (ie, estimate to 0.01 mL if buret has 0.1 ml divisions)

Explanation:

When we put a liquid in a pipette, we can see that the surface of that liquid will have a curve. This curve is called the meniscus and it has the correct volume that an aqueous solution has. However, for this, it is necessary that the meniscus is observed at eye level and that its edges and center are clearly visible.

Answer:

No change to the cation  Add -ide to the anion

Question 1 and .2

Explanation:

Answer:

The answer to this problem is C

Answer:

Kb[tex]= 1.58 * 10^{-6}[/tex]

Explanation:

The correct question is

What is Kb for N2H4 if the pH of a 0.158M solution of N2H5Cl is 4.5?

Solution-

N2H4Cl hydrolyses on addition of water

The reaction equation is as follows -

N2H4+ + H2O ----> N2H4 + H3O+

[tex]Ka = \frac{K_w}{K_b} = \frac{10^{-14}}{K_b}[/tex]

pH [tex]= 4.5[/tex]

[tex][H+] = 10^{-pH} = 10^{-4.5}[/tex]

[tex]K_b= \frac{10^{-14} }{K_b} = \frac{Y_2}{0.158} \\K_b= \frac{(10^{-4.5})^2}{0.158}\\=> Kb = 0.158 * 10-14 /(10-4.5)2[/tex]

 Kb[tex]= 1.58 * 10^{-6}[/tex]

Answer:

The metallic oxide is Li₂O

Explanation:

Let the metallic oxide be M₂O

Thus;

M₂O + H₂ = 2M + H₂O

Molar mass of M₂O = (2x + 16)

We assume Molar mass of M to be x.

We are told that 5.00 g of the metallic oxide produces 2.32 g of the metal.

By proportion, we can write the following;

5g of M₂O × (1 mole of M₂O/(2x + 16)) × (2 moles of M/1 mole of M₂O) = 2.32 g of M × 1 mole of M/x g of M

This cancels out to give us;

10/(2x + 16) = 2.32/x

Cross multiply to get;

10x = 2.32(2x + 16)

10x = 4.64x + 37.12

10x - 4.64x = 37.12

5.36x = 37.12

x = 37.12/5.36

x = 6.925 g/mol

The metal with a molar mass closest to this value of x is Lithium which has a molar mass of 6.94 g/mol

Thus the metal is Lithium and as such the metallic oxide is Li₂O

Answer:

Option B & Option C

Explanation:

correct on edge! :D

When chemicals combine chemical change takes place which is accompanied by emission of heat and light.

Chemical changes are defined as changes which occur when a substance combines with another substance to form a new substance.Alternatively, when a substance breaks down or decomposes to give new substances it is also considered to be a chemical change.

There are several characteristics of chemical changes like change in color, change in state , change in odor and change in composition . During chemical change there is also formation of precipitate an insoluble mass of substance or even evolution of gases.

There are three types of chemical changes:

1) inorganic changes

2)organic changes

3) biochemical changes

During chemical changes atoms are rearranged and changes are accompanied by an energy change as new substances are formed.

Learn more about chemical change,here:

https://brainly.com/question/23693316

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Answer: The activation energy Ea for this reaction is 22689.8 J/mol

Explanation:

According to Arrhenius equation with change in temperature, the formula is as follows.

[tex]ln \frac{k_{2}}{k_{1}} = \frac{-E_{a}}{R}[\frac{1}{T_{2}} - \frac{1}{T_{1}}][/tex]

[tex]k_1[/tex] = rate constant at temperature [tex]T_1[/tex] = [tex]2.3\times 10^8[/tex]

[tex]k_2[/tex] = rate constant at temperature [tex]T_2[/tex] = [tex]4.8\times 10^8[/tex]

[tex]E_a[/tex]= activation energy = ?

R= gas constant = 8.314 J/kmol

[tex]T_1[/tex] = temperature = [tex]280.0^0C=(273+280)=553K[/tex]

[tex]T_2[/tex] = temperature = [tex]376.0^0C=(273+376)=649K[/tex]

Putting in the values ::

[tex]ln \frac{4.8\times 10^8}{2.3\times 10^8} = \frac{-E_{a}}{8.314}[\frac{1}{649} - \frac{1}{553}][/tex]

[tex]E_a=22689.8J/mol[/tex]

The activation energy Ea for this reaction is 22689.8 J/mol

Answer:

88.46%

Explanation:

Percentage yield is actual/theoretical * 100

138/156 * 100 = 88.4615385

Answer:

Although you might think of a machine as complex system of gears, drive belts and and a motor, the definition physicists use is much simpler. A machine is simply a device that does work, and there are only six different types of simple machines. They include the lever, the pulley, the wheel and axle, the screw, the wedge and the inclined plane.

Explanation:

Answer:

ok

Explanation:

Among the given options the compound with the formula C₃H₈ is option C. It is an organic compound under named as propane.

What is propane?

Propane is an organic compound classified as a hydrocarbon  with saturated carbon - hydrogen bonds. It's formula is C₃H₈. It contains 3 carbons and 8 hydrogens.

The two end carbons contains 3 hydrogens each and the middle carbon contains 2 hydrogens. They are all bonded through sigma bonding. The compound in A is C₅H₁₂ and in B, it is C₆H₁₄.

The formula of the compound in option D is C₅H₁₀. Hence, the skeleton showing the compound with the formula of C₃H₈ is option C.

To find more on propane, refer here:

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Answer:

no, and next time take it right

Explanation:

Answer:

5. higher

6. shifted down

7. closer together  

8. increase its wave length

Explanation:

Answer:

See answer below

Explanation:

Let's write the equation again:

H₂ + O₂ ---------> H₂O

Now that we have written the equation, let's solve the exercise:

1. In this case, we first need to make a difference between atom and molecule. An atom is just a single element, a molecule it's when you have more than 1 element in a compound.

Knowing this, we have the H₂. In this case we only have one element, Hydrogen. However, as you can see in the expression, we have a number 2 as a subscript. The number 2 means that the hydrogen it's not alone, we do not have one hydrogen, we have two hydrogens, therefore, it becomes a molecule. Now, This molecule, according to the number 2 as subscript, means that the molecule of hydrogen have 2 atoms of hydrogens, and this formed the molecule, therefore, there are 2 atoms of hydrogens in H₂.

2. Following the same explanation of above, but using oxygen, we have the same thing, so, in a molecule of O₂, we have 2 atoms of oxygen.

3. The molecule of water is composed of Hydrogen and oxygen. As you can see, in this case we have 2 hydrogen and 1 oxygen, therefore, in 1 molecule of water, there are 1 atom of oxygen and 2 atoms of hydrogen.

4. The subscript, as you may know now, tell us the number of atoms that you have in a molecule or compound. This number also means, in different compounds the oxidation state of the atoms that conform the molecule.

5. No, the equation is not balanced, because we do not have the same number of oxygen on the side of the products. We need to balance that. As the oxygen is unbalanced, we just need to put numbers as coefficients, behind the molecule. This number will multiply the number of atoms of the referred molecule. So, doing this with the water on the products to equal the number of oxygen, we have:

H₂ + O₂ ---------> 2H₂O

But this 2, unbalance at the same time the number of hydrogens. We now have 4 hydrogens in the product, so, to balance this, we put a 2 on the reactants:

2H₂ + O₂ ---------> 2H₂O

Now the reaction is balanced.

Hope this helps

Answer:

0.71 g/cm^3

Explanation:

Density = Mass ÷ Volume

So you would do 112.5 ÷ 159.3 which gives the result 0.71

Answer:

Number of moles = 0.1179 (Approx)

Explanation:

Given:

Mass of LiCl = 5 grams

Molar mass of LiCl = 42.39 g

Find:

Number of moles

Computation:

Number of moles = Mass / Molar mass

Number of moles = 5 / 42.39

Number of moles = 0.1179 (Approx)

Answer:

D) Vitamin C is oxidized to yield a furan ring with 3 carbonyl groups and no double bonds

Explanation:

We can tell that the compound " (5R)-5-[(1S)-1,2-dihydroxyethyl]-3,4-dihydroxy-furan-2,3,4(5H)-trione " has 3 carbonyl groups due to it having "trione" in the name (and it lacking other carbonyl group names, like amide or carboxylic acid).

As there is no "-ene" part of the name referencing a double bond, the only option left is option D).

Answer: The new temperature of the water bath is [tex]31.9^0C[/tex]

Explanation:

The quantity of heat required to raise the temperature of a substance by one degree Celsius is called the specific heat capacity.

[tex]Q=m\times c\times \Delta T[/tex]

Q = Heat released by water =[tex]69.0kJ=69000J[/tex]     (1kJ=1000J)

m= mass of water = 8.10 kg= 8100 g   (1kg=1000g)

c = specific heat capacity = [tex]4.184J/g^0C[/tex]

Initial temperature of the water = [tex]T_i[/tex] = [tex]33.9^0C[/tex]

Final temperature of the water = [tex]T_f[/tex]  = ?

Change in temperature ,[tex]\Delta T=T_f-T_i[/tex]

Putting in the values, we get:

[tex]-69000J=8100g\times 4.184J/g^0C\times (T_f-33.9)^0C[/tex]

[tex]T_f=31.9^0C[/tex]

The new temperature of the water bath is [tex]31.9^0C[/tex]

Answer:

3 mol AlCl₃.

Explanation:

Hello!

In this case, according to the specified reactants and products, it is possible to set up the following balanced chemical reaction:

[tex]Al(NO_3)_3+3NaCl\rightarrow 3NaNO_3+AlCl_3[/tex]

Whereas we evidence the 1:3 mole ratio between aluminum nitrate and sodium chloride; thus, since different moles were reacting, we need to identify the limiting reactant by computing the moles of AlCl₃ produced by each reactant as follows:

[tex]n_{AlCl_3}^{by\ Al(NO_3)_3}=4molAl(NO_3)_3*\frac{1molAlCl_3}{1molAl(NO_3)_3} =4molAlCl_3\\\\n_{AlCl_3}^{by\ NaCl}=9molNaCl*\frac{1molAlCl_3}{3molNaCl} =3molAlCl_3[/tex]

Thus, we infer that NaCl is the limiting reactant as it produces the fewest moles of AlCl₃; consequently the produced amount of this product is 3 mol.

Best regards!

Answer:

the answer is 1,2,2,3

Explanation:

Fe3O4 +C ---> CO2 + Fe

1Fe3O4 +2C ---> 2CO2 + 3Fe

Answer:

22 g of water

Explanation:

The balanced chemical equation is:

H₂SO₄(aq) + 2 NaOH(aq) → Na₂SO₄(aq) +2 H₂O(l)

⇒ 1 mol of H₂SO₄ reacts with 2 moles of NaOH to produce 2 moles of H₂O.

First, we have to convert the moles to grams by using the molecular weight (Mw) of each compound:

        mass of H₂SO₄ = moles x Mw = 1 mol x 98 g/mol = 98 g

        mass of NaOH = 2 moles x 40 g/mol = 80 g

        mass of NaOH = 2 moles x 18 g/mol = 36 g

Now, we have to determine which is the limiting reactant. The stroichiometric ratio is 98 g H₂SO₄/80 g NaOH. We have 86.9 g of NaOH, so we need the following amount of H₂SO₄:

98 g H₂SO₄/80 g NaOH x 86.9 g NaOH = 106.4 g H₂SO₄

As we need more H₂SO₄ (106.4 g) than we have (59 g), the limiting reactant is H₂SO₄.

Finally, we calculate the mass of H₂O produced with the limiting reactant. The stoichiometric ratio is 36 g H₂O/98 g H₂SO₄, so we multiply the actual mass of H₂SO₄ by the stoichiometric ratio to calculate the maximum mass of H₂O produced:

mass of H₂O = 36 g H₂O/98 g H₂SO₄ x 59 g H₂SO₄ = 21.7 g ≅ 22 g

Answer:

a)

[tex]K = 2.64 * 10^{-8}[/tex]

b)

[tex]15 \frac{5}{8}[/tex] hours

Explanation:

Given

Surface Area (S) of 250 grams of powder sample [tex]= 250[/tex] square meter.

[tex]S = 2500000[/tex] square centimeter

[tex]V\frac{dC}{dT} = 0.40[/tex] grams/minute

[tex]V\frac{dC}{dT} = \frac{dM}{dT} = \frac{0.40*60}{10} = 0.66[/tex] mg per second

[tex]C_s = 0.01[/tex] gram per cubic meter [tex]= 10[/tex] mg/ml

a)

[tex]\frac{dM}{dT} = K SC_s[/tex]

[tex]0.66 = K* 2500000* 10\\[/tex]

[tex]K = 2.64 * 10^{-8}[/tex] cm /sec

b) Time taken

Time taken to sink

[tex]\frac{10*60}{0.4} * 37.5 = 56,250[/tex]

Time in hours

[tex]15 \frac{5}{8}[/tex] hours

Answer:

Kinetic

Explanation:

When the ball is falling towards the table, it has kinetic energy. This elastic potential energy is why the ball is able to bounce, or rebound. After the ball rebounds, the elastic potential energy is transformed into kinetic energy, but it will never possess as much kinetic energy as during its original fall.

Answer:

Explanation:

It has kinetic energy.

Hope it helped you.

Answer:

Explanation:

Iron Haber process  = (making ammonia)

Vanadium (V) oxide = Contact process (a stage in making sulfuric acid)

Manganese dioxide = Decomposition of hydrogen peroxide (produces water and oxygen)

Answer:

2

Explanation

It seems logical

Answer:

the answer p+n

Explanation: