A car travels for 0.5 hours and goes 25 miles. What is the car's speed? (Remember sad + t)

Answer:

The Group 1 elements in the periodic table are known as the alkali metals. They include lithium, sodium and potassium, which all react vigorously with water to produce an alkaline solution.

Explanation:

Answer:

The moon is only visible during part of each month. ... When the moon is opposite the sun in the sky (which is when full moon happens), it will rise as the sun sets and set as the sun rises. Therefore, a full moon will be up all night long, but not during the day.

Explanation:

During full moon, the sun and moon will be in opposite sides. The illuminated portions of moon can be seen only in night in earth.

Full moon appears once in a every lunar cycle. That is the full part of moon is visible at this time. After the first two quarters, moon passes to waxing gibbous state, and then turns to full moon.

The moon's lit side faces earth's night side at the time of the full moon, when the sun and moon are on opposite sides of the planet. Therefore, a full moon is  only visible at night.

It is quite possible that you saw a full moon at least one day before or after the real full moon  phase if you have ever seen one shortly after dawn or just before sunset.

Rarely, under ideal circumstances, you could even be able to view a real full moon rising or setting opposite the sun, quite near the horizon. However, the moon typically never rises over the horizon.

Find more on full moon:

https://brainly.com/question/15024267

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Answer:

Answer:

i

[tex]J_{m} = 20 [/tex]

ii

[tex]J_{m} = 22.5 [/tex]

Explanation:

From the question we are told that

  The first temperatures is [tex]T_1 =  25^oC =  25 +273 =298 \ K[/tex]

   The second temperature is  [tex]T_2 =  100^oC =  100 +273 = 373 \ K[/tex]

Generally the equation for  the most highly populated rotational energy level is mathematically represented as

     [tex]J_{m} = [ \frac{RT}{2B}]  ^{\frac{1}{2} } - \frac{1}{2}[/tex]

Here R is the gas constant with value [tex]R =8.314 \ J\cdot K^{-1} \cdot mol^{-1}[/tex]

Also  

      B is given as [tex]B=\ 0.244 \ cm^{-1}[/tex]

   Generally the energy require per mole to move 1 cm is  12 J /mole

So   [tex]0.244 \ cm^{-1}[/tex]  will require x J/mole

           [tex]x =  0.244 *  12[/tex]

=>          [tex]x =  2.928 \ J/mol [/tex]

So at the first temperature

     [tex]J_{m} = [ \frac{8.314 * 298  }{2*  2.928 }]  ^{\frac{1}{2} } - 0.5 [/tex]

=>  [tex]J_{m} = 20 [/tex]

So at the second temperature

           [tex]J_{m} = [ \frac{8.314 * 373  }{2*  2.928 }]  ^{\frac{1}{2} } - 0.5 [/tex]

=>  [tex]J_{m} = 22.5 [/tex]

Answer:

ARSENIC

Explanation:

It has an atomic number of 33

Answer:

Explanation:

half life = 4 h

initial concentration = 100

final concentration = 15

Time = t

No of half life  x = t / 4

15 = 100 x ( 1/2 )ˣ

.15 =  ( 1/2 )ˣ

ln .15 = - x ln2

x = - ln .15 / ln 2

= 1.897 / .693

x = 2.737

x = t / 4

t = 2.737 x 4 = 11 h approx .

the bigger the object the more weight of the planet or gravity is acted upon if

Answer:

6.72M of HNO3

Explanation:

In the problem you are diluting the original HNO3 solution by the addition of some water. The final volume is:

290.7mL + 350.0mL = 640.7mL

And you are diluting the solution:

640.7mL / 350.0mL = 1.8306 times

As the original concentration was 12.3M, the final concentration will be:

12.3M / 1.8306 =

Answer:

[tex]M=44.06\frac{g}{mol}[/tex]

Explanation:

Hello.

In this case, knowing the temperature, density and temperature of Y which behaves ideally, we can write the ideal gas equation:

[tex]PV=nRT[/tex]

Whereas the moles are equal to the mass over the molar mass of Y:

[tex]PV=\frac{m}{M} RT[/tex]

Thus, solving for the molar mass we write:

[tex]M=\frac{mRT}{PV}[/tex]

Yet, since density is mass of over volume, we then write:

[tex]M=\frac{\rho RT}{P}[/tex]

Considering the pressure in atm and the density in g/L:

[tex]P=95.3kPa*\frac{1atm}{101.325kPa}=0.941atm\\\\\rho=1.696\frac{g}{dm^3} *\frac{1dm^3}{1L}=1.696\frac{g}{L}[/tex]

Therefore, by plugging the values in, we obtain:

[tex]M=\frac{1.696\frac{g}{L} *0.082\frac{atm*L}{mol*K}*298K}{0.941atm}\\\\M=44.06\frac{g}{mol}[/tex]

Thus, the gas may be propane ([tex]C_3H_8[/tex]) since it molar mass is 44.11 g/mol.

Best regards!

Answer: It is the principle that matter cannot be created or destroyed.

Explanation:

Answer:

Wadding is a disc of material used in guns to seal gas behind a projectile or to separate powder from shot. ... Wadding for muzzleloaders is typically a small piece of cloth, or paper wrapping from the cartridge.

Explanation:

Answer:

a) - 0.2 M

b) - 0.2 M

c)- 0

Explanation:

The chemical formula of copper (II) bromide is CuBr₂. Its molar mass (MM) is calculated as follows:

MM(CuBr₂)= MM(Cu) + (2 x MM(Br) = 63.5 g/mol + (2 x 80 g/mol)= 223.5 g/mol

a). Molarity = moles CuBr₂/1 L solution

moles CuBr₂ = mass/MM = 18.7 g x 1 mol/223.5 g = 0.084 mol

Volume in L = 375 mL x 1 L/1000 mL = 0.375 L

M = 0.084 mol/(0.375 L) = 0.223 M ≅ 0.2 M

b). When is added to water, CuBr₂ dissociates into ions as follows:

CuBr₂ ⇒ Cu²⁺ + 2 Br⁻

We have 1 mol Cu²⁺ (copper (II) cation) per mol of CuBr₂. Thus, the concentration of copper (II) cation is:

0.2 mol CuBr₂ x 1 mol Cu²⁺/mol CuBr₂ = 0.2 M

c). The concentration of acetate anion is 0. There is no acetate anion in the solution (the anion from CuBr₂ is bromide Br⁻).

Answer:

d) The rate of forward reaction equals the rate of the reverse reaction

Explanation:

A dynamic equilibrium is attained when the rate of forward reaction is the same as reverse reaction. It occurs majorly in a reversible reaction. Thus, no change occurs in the reaction.

The process can be control by the immediate removal of the product as it is formed. This ensure that the reaction stops when all reactants are used up.

Complete question is;

What is the frequency of light emitted when the electron in a hydrogen atom undergoes a transition from energy level n=6 to level n=3?

Answer:

Frequency = 2.742 × 10^(14) s^(-1)

Explanation:

First of all, the energy of hydrogen electron from online values is;

E_n = -2.18 × 10^(-18) × (1/n²) J

n is the principal quantum number

We are told that hydrogen atom undergoes a transition from energy levels n = 3 to n = 6.

Thus, it means we have to find the difference between the electrons energy in the energy levels n = 3 to n = 6.

Thus;

E_n = E_6 - E_3

Thus;

E_n = [-2.18 × 10^(-18) × (1/6²)] - [-2.18 × 10^(-18) × (1/3²)]

E_n = (2.18 × 10^(-18)) × [-1/36 + 1/9]

E_n = 0.1817 × 10^(-18) J

From Planck expression, we can find the frequency. Thus;

E = hf

Where h is Planck's constant = 6.626 × 10^(-34) m²kg/s

Thus;

0.1817 × 10^(-18) = 6.626 × 10^(-34) × f

f = (0.1817 × 10^(-18))/(6.626 × 10^(-34))

f = 2.742 × 10^(14) s^(-1)

Answer:

Percentage yield of carbon dioxide is 49.9%

Explanation:

We'll begin by writing the balanced equation for the reaction. This is illustrated below:

2CH3(CH2)2CH3 + 13O2 —> 8CO2 + 10H2O

OR

2C4H10 + 13O2 —> 8CO2 + 10H2O

Next, we shall determine the masses of butane and oxygen that reacted and the mass of carbon dioxide produced from the balanced equation. This is illustrated below:

Molar mass of butane C4H10 = (12×4) + (10×1)

= 48 + 10

= 58 g/mol

Mass of C4H10 from the balanced equation = 2 × 58 = 116 g

Molar mass of O2 = 16 × 2 = 32 g/mol

Mass of O2 from the balanced equation = 13 × 32 = 416 g

Molar mass of CO2 = 12 + (16×2)

= 12 + 32

= 44 g/mol

Mass of CO2 from the balanced equation = 8 × 44 = 352 g

Summary:

From the balanced equation above,

116 g of butane reacted with 416 g of oxygen to produce 352 g of carbon dioxide.

Next, we shall determine the limiting reactant. This can be obtained as follow:

From the balanced equation above,

116 g of butane reacted with 416 g of oxygen.

Therefore, 34.29 g of butane will react with = (34.29 × 416) / 116 = 122.97 g of oxygen.

From the calculation made above, we can see clearly that only 122.97 g out of 165.7 g of oxygen reacted completely with 34.29 g of butane. Therefore, butane is the limiting reactant and oxygen is the excess reactant.

Next, we shall determine the theoretical yield of carbon dioxide.

In this case, we shall use the limiting reactant because it will give the maximum yield of carbon dioxide as all of it is used up in the reaction.

The limiting reactant is butane and the theoretical yield of carbon dioxide can be obtained as follow:

From the balanced equation above,

116 g of butane reacted to produce 352 g of carbon dioxide.

Therefore, 34.29 g of butane will react to produce = (34.29 × 352) / 116 = 104.05 g of carbon dioxide.

Therefore, the theoretical yield of carbon dioxide is 104.05 g

Finally, we shall determine the percentage yield of carbon dioxide as follow:

Actual yield of carbon dioxide = 51.9 g

Theoretical yield of carbon dioxide = 104.05 g

Percentage yield of carbon dioxide =?

Percentage yield = Actual yield /Theoretical yield × 100

Percentage yield of carbon dioxide = 51.9 / 104.05 × 100

Percentage yield of carbon dioxide = 49.9%

Answer:

the process of plants taking the sunlight and turning it into food for the plant.

Explanation:

Answer:

Reactions of Metals with Water

Metals with moderate to low reactivity react very slowly with water. However, they react moderately with steam when heated and give hydrogen gas and metal oxides. Metals low in the metal reactivity series do not react with water even at high temperature.

Explanation:

Order of reactivity                     Metal               Reactions with water or steam

↑                                           sodium (Na)         Vigorous reaction with cold water

↓                                        calcium (Ca)    Less vigorous reaction with cold water

least reactive           magnesium (Mg)    Slow reaction with cold water, vigorous                                                                                                   .                                                                 with hot water

Answer:

1.61 x 10²⁰ molecules

Explanation:

Given parameters:

Mass of the hydrogen gas  = 8.01 x 10⁻⁴g

Unknown

Number of molecules of NH₃ = ?

Solution:

Given reaction:

                     N₂  +  3H₂   →   2NH₃

We have to solve from the known to the unknown

             find the number of moles of the specie;

    number of moles = [tex]\frac{mass}{molar mass}[/tex]

     Molar mass of H₂ = 2(1) = 2g/mol

   Number of moles  = [tex]\frac{0.0008}{2}[/tex]   = 0.0004mol

      0.0004 moles of H₂ will produce [tex]\frac{0.0004 x 2}{3}[/tex]   = 0.00027moles of NH₃

   1 mole of a substance contains 6.02 x 10²³ molecules

     0.00027mole of NH₃ will contain 0.00027 x 6.02 x 10²³

                               = 1.61 x 10²⁰ molecules

Answer:

See explanation

Explanation:

a) -About 1-2 drops of the unknown is dissolved in approximately 1 mL of analytical grade acetone standard solution. The test solution is added and shaken thoroughly.  If a positive test is not immediately observed, the set should be allowed to stand for 1-2 minutes. A positive result means the appearance of a green color.

b) The functional groups that can be distinguished by the test are alcohols and aldehydes.

Aldehydes give a positive test to chromic acid but ketones do not.

Primary and secondary alcohols give a positive test to chromic acid but tertiary alcohols do not.

c) Chromic Acid Test involves Cr in the +6 oxidation state. A positive test implies the reduction of orange Cr^6+ to green chromium Cr^3+.

d) The compounds were not shown but this image attached from lumen learning summarizes the reaction mechanism of chromic acid test.

Answer:

1. 14 moles of NH3 were produced.

2. 7 moles of CO2 were produced.

3. 7 moles of H2O were produced.

Explanation:

We'll begin by writing a balanced equation for the decomposition of ammonium carbonate, (NH4)2CO3.

This is illustrated below:

(NH4)2CO3(s) —> NH3(g) + CO2(g) + H2O(g)

There are 2 atoms of N on the left side and 1 atom on the right side. It can be balance by putting 2 in front of NH3 as shown below:

(NH4)2CO3(s) —> 2NH3(g) + CO2(g) + H2O(g)

Now the equation is balanced.

From the balanced equation above,

1 mole of (NH4)2CO3 decompose to produce 2 moles of NH3, 1 mole of CO2 and 1 mole of H2O.

1. Determination of the number of mole of NH3 produced.

From the balanced equation above,

1 mole of (NH4)2CO3 decompose to produce 2 moles of NH3.

Therefore, 7 moles of (NH4)2CO3 will decompose to produce = 7 × 2 = 14 moles of NH3.

Therefore, 14 moles of NH3 were produced.

2. Determination of the number of mole CO2 produced.

From the balanced equation above,

1 mole of (NH4)2CO3 decompose to produce 1 mole of CO2.

Therefore, 7 moles of (NH4)2CO3 will also decompose to produce 7 moles of CO2.

Therefore, 7 moles of CO2 were produced.

3. Determination of the number of mole of H2O produced.

From the balanced equation above,

1 mole of (NH4)2CO3 decompose to produce 1 mole of H2O.

Therefore, 7 moles of (NH4)2CO3 will also decompose to produce 7 moles of H2O.

Therefore, 7 moles of H2O were produced.

Answer:

H. 2 blue, 3 yellow, and 12 green

Explanation:

Aluminium atoms (Al) = Blue Beads

Oxygen Atoms (O) = Green Beads

Sulfur (S) = Yellow beads

From the compound Al2(SO4)3, the number of atoms present are;

Al = 2

S = 3

O = 12

This means the model would contain;

2 Blue beads

12 Green beads

3 Yellow beads

The correct option is; H. 2 blue, 3 yellow, and 12 green

Answer:

H

Explanation:

Al(blue):2

S(yellow):3

O(green):4*3=12

so 2 blue beads 3 yellow beads and 12 green beads don't time the 2*3 it's not the same compound

good luck!!!

Answer:

gill lamellae

Explanation:

Gills  in fishes are structures that permit fish to carry out gaseous exchange in water.  Fishes exchange gases  such as oxygen and carbon dioxide using gills.

Fish gills carry out their activity mainly through its major component called the  gill lamellae. These are comb-like filaments which help increase the surface area of the gills in order to facilitate gaseous exchange

Answer: Chlorine.

Explanation:

Since chlorine's 17 protons are greater than magnesium's 12 protons, chlorine will have a greater effective nuclear charge to draw chlorine's valence electrons closer to the nucleus and, thus, chlorine is expected to have the smaller atomic radius, while magnesium with the lower effective nuclear charge is expected to have a smaller amount of radius.

Answer:

D

Explanation:

i did it before

Answer: The largest one, and answer is Sand

Explanation:

Answer:

humus

Explanation:

Answer:

2.01 g H₂

Explanation:

The chemical equation for the electrolysis of water is

2 H₂O  ⇒  2 H₂  +  O₂

Convert grams of water to moles.  The molar mass of water is 18.016 g/mol.

(36 g)/(18.016 g/mol) = 1.998 mol H₂O

Convert moles of water to moles of hydrogen by using the mole ratio.  By looking at the chemical equation, you can see that for every 2 moles of water consumed, 2 moles of hydrogen is produced.

(1.998 mol H₂O) × (2 mol H₂/2 mol H₂O) = 1.998 mol H₂

Now that you have moles of hydrogen, you can convert to grams.  The molar mass of hydrogen is 1.008 g/mol.

(1.998 mol) × (1.008 g/mol) = 2.01 g H₂

You will produce 2.01 grams of hydrogen

Answer:

Approximately [tex]92.9\; \rm mL[/tex].

Explanation:

Look up relevant relative atomic mass data on a modern periodic table:

Calculate the formula mass of [tex]\rm Al_2(SO_4)_3[/tex]:

[tex]M(\mathrm{Al_2(SO_4)_3}) = 2 \times 26.982 + 3 \times (32.06 + 4 \times 15.999) = 342.132\; \rm g \cdot mol^{-1}[/tex].

Calculate the number of moles of [tex]\rm Al_2(SO_4)_3[/tex] formula units that corresponds to [tex]110\; \rm g[/tex]:

[tex]\displaystyle n(\mathrm{Al_2(SO_4)_3}) = \frac{m}{M} = \frac{110\; \rm g}{342.132\; \rm g \cdot mol^{-1}} \approx 0.322\; \rm mol[/tex].

Calculate the volume of a [tex]3.25\; \rm M[/tex] [tex]\rm Al_2(SO_4)_3[/tex] solution that would contain [tex]0.322\; \rm mol[/tex] of [tex]\rm Al_2(SO_4)_3\![/tex] formula units. Note, that the unit of concentration "[tex]\rm M[/tex]" is equivalent to [tex]\rm mol \cdot L^{-1}[/tex].

[tex]\displaystyle V = \frac{n}{c} = \frac{0.322\; \rm mol}{3.25\; \rm mol \cdot L^{-1}} \approx 0.0989\; \rm L[/tex].

Convert that to milliliters as requested:

[tex]\displaystyle V \approx 0.0989\; \rm L \times \frac{1000\; \rm mL}{1\; \rm L} = 98.9\; \rm mL[/tex].

Answer:

less, decreases

Explanation:

When the pressure of an atmosphere occurs because of the force exerted so at the time of the higher altitudes, the air mass i.e. above the earth should be less as the air is attracted towards surface of an earth because of the gravity and air contains the mass that shows near the surface area so automatically the air density reduced due to which the mass also decreased

Answer:

d

Explanation:

collagen is made of proteins