answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
7nadin3 [17]
1 year ago
10

For a school event 1/6 of the athletic field is reversed for the fifth -grade classes the reserved part of the field is divided

equally Among the 4 fifth grade classes in the school what fraction of the whole athletic field is reserved for each fifth class
Chemistry
1 answer:
SVETLANKA909090 [29]1 year ago
3 0

Answer:

\frac{1}{24}

Explanation:

Given:

For a school event, 1/6 of the athletic field is reserved for the fifth -grade classes and the reserved part of the field is divided equally among the 4 fifth grade classes in the school.

To find: fraction of the whole athletic field reserved for each fifth class

Solution:

Fraction of the whole athletic field reserved for four fifth classes = \frac{1}{6}

So, fraction of the whole athletic field reserved for each fifth class = \frac{1}{4}(\frac{1}{6})=\frac{1}{24}

You might be interested in
Beer brewing begins with steeping grains in hot water, releasing the sugars inside. The sugar water is then heated to a boil and
user100 [1]

Answer:

The answers to the question are

a. 166.64 ° F

b. 217990.08 J/hour or 60.55 J/s = 60.55 watts

c. 13.C

Explanation:

a. To solve the question we list out the given variables thus

mass of grain = 16.5 lbs

Temperature of grain = 67 °F

Volume of hot water = 5 gals = ‪0.02273‬ m³

Equilibrium temperature of the mixture = 154 °F

Specific heat capacity of the grain = 0.44 times specific heat capacity  of water

Therefore we have

Heat supplied by hot water = heat gained by mixture

Density of the water = 997 kg/m³ which gives

Therefore the mass of the water = (Density of the water) × (Volume of the water) = (997 kg/m³) × ‪(0.02273‬ m³) = 22.66181 kg

Therefore the heat supplied by the water =22.66 kg×1000 g/kg ×4.2 J/g°C×(Tₓ -‪67.78 °C) = ‪7.48 kg×1000 g/kg×0.44×4.2 J/g°C×(67.78 -‪19.44)

= 95172 × (Tₓ -‪67.78 °C) =668205.7536 J

(Tₓ -‪67.78 °C) = 7.02 from where Tₓ = 74.80 °C = ‪166.64 ° F

The initial temperature (strike temperature) of the hot water = 74.80 °C = 166.64 ° F

b. Where the mixture lost two degrees we have

22.66 kg×1000 g/kg ×4.2 J/g°C×2 °C + ‪7.48 kg×1000 g/kg×0.44×4.2 J/g°C×2  °C = 217990.08 J therefore the average energy lost per unit time = 217990.08 J/hour or 60.55 J/s

c. To find out how much it cost we have

Heat energy required to raise 5 gallons of water from 110 °F to 166.64 °F we have

22.66 kg×1000 g/kg ×4.2 J/g°C×(74.8 °C-‪43.33 °C) = 2994745.92 J

Energy lost during the heating = 10% = 299474.59 J

Total energy supplied 2994745.92 J + 299474.59 J  = 3294220.5 J

Time for heating = 47 minutes, therefore rate of energy consumption = (3294220.5 J)/ (47×60) = 1168.163 Watt 1.168 kW

Cost of energy = 15.C per kilowatt-hour therefore 1.168 kW for 47 minutes will cost

1.168 kW ×47/60×15 = 13.C

therefore it cost 13.C to heat the 5 gallons of tap water initially at 110 ° F to the strike temperature 166.64 °F

6 0
1 year ago
Two weak acids, A and B, have pKa values of 4 and 6, respectively. Which statement is true?A) Acid A dissociates to a greater ex
zalisa [80]

Answer:

A) Acid A dissociates to a greater extent in water than acid B

Explanation:

A) Acid A dissociates to a greater extent in water than acid B

We are given the pKa for both acids, and we know

pKa = - log Ka

Taking antilog to both sides of the equation we can solve for Ka

⇒ -pKa = log Ka

-antilog pKa = Ka

10 ^-pka = Ka

So ka for acid A = 10⁻⁴

and

ka for acid B = 10⁻⁶

True the equilibrium constant for acid A is greater, so it dissociates more.

B) For solutions of equal concentration, acid B will have a lower pH.

We know the stronger acid is A, and it dissociates more. Since pH is the negative log of H₃O⁺ concentration, it follows that at equal concentrations the acid A will have at equilibrium a greater [H₃O⁺] and hence a lower pH

C) B is the conjugate base of A

False:

If B were the conjugate base of A, its  Kb would have been given by:

Ka x Kb = Kw

Kb = 10⁻¹⁴/10⁻⁶ = 10⁻⁸ for the conjugate base of acid B

Kb = 10⁻¹⁴/10⁻⁴ = 10⁻¹⁰ for the conjugate base of acid A

which are not equal.

D) Acid A is more likely to be a polyprotic acid than acid B.

False

Just having the pkas for both acids one cannot know if any of the acids is polyprotic. We will need the formula for the acids.

E) The equivalence point of acid A is higher than that of acid B

False

The equivalence point depends on the the concentration of the acids  and their volumes.

The equivalence point is reached in the titration when the number of equivalents of base equals the number of equivalents of acid:

# equivalents acid = # equivalents of base  @ end point

and

# equivalents acid = Molarity of acid x Volume of acid

4 0
2 years ago
The data in the table below were obtained for the reaction: 2clo2 (aq) + 2 oh- (aq) --> clo3- (aq) + clo2- (aq) + h2o (l) exp
SVETLANKA909090 [29]
Lets organise the data given in the question
                [ClO₂] (m)       [OH⁻] (m)        initial rate (m/s)
                  <span>0.060              0.030               0.0248
</span><span>                  0.020              0.030               0.00276
</span><span>                  0.020              0.090                0.00828
rate equation as follows 
rate = k [</span>ClO₂]ᵃ [OH⁻]ᵇ
where k - rate constant 
we need to find order with respect to ClO₂ therefore lets take the 2 equations where OH⁻ is constant.
1) 0.00276 = k [0.020]ᵃ[0.030]ᵇ
2) 0.0248 = k [0.060]ᵃ[0.030]ᵇ
divide first equation from the second
0.0248/0.00276 = [0.060/0.020]ᵇ
8.99 = 3ᵇ
8.99 rounded off to 9
9 = 3ᵇ
b = 2
order with respect to ClO₂ is 2
3 0
1 year ago
1. A student performs a reaction in a beaker by reaction silver nitrate with one long copper wire. The student’s thermometer cha
stiv31 [10]

Explanation:

The observation of student was that thermometer reading changed from 27°C to 35°C which indicates that temperature of the beaker solution rose after reaction due to release of heat during reaction as a product.

Those chemical reactions which gives heat energy as a product into their surrounding are categorized as exothermic reactions. During the course of these reaction temperature of the surroundings also increased.

So, this means that reaction between silver nitrate and copper wire is an exothermic reaction.

Three ways that the student could speed up the reaction :

  • By adding catalyst to the reaction.
  • By decreasing the temperature.
  • By increasing the concentration of silver nitarte solution.
3 0
2 years ago
Read 2 more answers
Select all the true statements. Group of answer choices The +3 oxidation state is characteristic of the actinides. All actinides
Tanya [424]

Answer:

The +3 oxidation state is characteristic of the actinides.

All actinides are radioactive.

Cerium (Ce) rnakes 100th in abundance (by mass %).

The actinides are silvery and chemically reactive.

8 0
2 years ago
Other questions:
  • At STP, the element oxygen can exist as either O2 or O3 gas molecules. These two forms of the element have(1) the same chemical
    13·2 answers
  • A gas can holds 2.9 gal of gasoline.<br><br><br> What is this quantity in cubic centimeters?
    5·1 answer
  • 6. A rectangular block of wood has length 6.0 cm, width 5.0 cm and height 10.0 cm. It has mass l50g. What is the mass of a block
    7·1 answer
  • You have 3.50 l of solution that contains 90.0 g of sodium chloride, nacl. what is the molar mass of nacl? what is the molarity
    9·1 answer
  • Hbr addition to an alkene is a ch221 reaction with which you should be familiar. when peroxides are present, one regioisomer is
    5·1 answer
  • The force of attraction between a divalent cation and a divalent anion is 1.91 x 10-8 n. If the ionic radius of the cation is 0.
    10·1 answer
  • N a football game, two players tackle each other so hard that they both fly in opposite directions after they hit each other. �W
    10·1 answer
  • You need to prepare 2.00 L of 0.100 M Na2CO3 solution. The best procedure is to weigh out: ___________
    8·2 answers
  • 3.4 moles of solid CuSO4 is added to 1.8 L of water and allowed to dissolve. Will all the solid dissolve?
    8·1 answer
  • 500 mL of He at 300 K is heated to 450 K. Find V2
    6·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!