1answer.
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
hichkok12 [17]
3 years ago
13

At 1 atm, how much energy is required to heat 39.0 g of h2o(s at –24.0 °c to h2o(g at 121.0 °c?

Chemistry
1 answer:
earnstyle [38]3 years ago
4 0
Q = mcΔt, q = energy [J] m = mass (of water) [g]; c = specific heat capacity of water [J g⁻¹ K⁻¹/°C⁻¹]; Δt = change in temperature [K/°C]
Δt = 121 - -24 = 145
q = 39 × 4.18 × 145
q = 23637.9 J
You might be interested in
The following data is given to find the formula of a Hydrate:
umka21 [38]

The masses can be found by substractions:

  • Mass of CaSO₄.H2O (hydrate):

16.05 g - 13.56 g = 2.49 g

  • Mass of CaSO₄ anhydrate:

15.07 g - 13.56 g = 1.51 g

  • The mass of water is equal to the difference between the mass of the hydrate and the mass of the anhydrate:

2.49 g - 1.51 g = 0.98 g

  • The percent of water is found by the formula:

massWater ÷ massHydrate * 100%

0.98 g ÷ 2.49 g * 100% = 39.36%

  • The mole of water is calculated using water's molecular weight (18g/mol):

0.98 g ÷ 18 g/mol = 0.054 mol water

  • A similar procedure is made for the mole of salt (CaSO₄ = 136.14 g/mol)

1.51 g ÷ 136.14 g/mol = 0.011 mol CaSO₄

  • The ratio of mole of water to mole of anhydrate is:

0.054 mol water / 0.011 mol CaSO₄ = 0.49

In other words the molecular formula for the hydrate salt is CaSO₄·0.5H₂O

3 0
3 years ago
34. An electron in the 3d state of the hydrogen atom has a radial part of the wave function of the form A r2 exp(-r/3ao). What i
nikdorinn [45]

Answer: Option (e) is the correct answer.

Explanation:

Formula to calculate radius is as follows.

          p(r) = Ar(r^{2}e^{\frac{-r}{3a_{o}}}

                = Ar^{3}e^{\frac{-r}{3a_{o}}}

     \frac{dp(r)}{dr} = 0

            Ar^{3}e^{\frac{-r}{3a_{o}}}(\frac{-1}{3a_{o}} + Ae^{\frac{-r}{3a_{o}}}(3r^{2}) = 0

                     \frac{Ar^{3}}{3a_{o}}e^{\frac{-r}{3a_{o}}}

                      = 3Ar^{2}e^{\frac{-r}{3a_{o}}}

                       r = 9a_{o}

Thus, we can conclude that most likely radius at which the electron would be found is 9a_{o}.

4 0
3 years ago
How many moles of KBr are present in 500 ml of a 0.8 M KBr solution?
faltersainse [42]

Answer:

2) 0.4 mol

Explanation:

Step 1: Given data

  • Volume of the solution (V): 500 mL
  • Molar concentration of the solution (M): 0.8 M = 0.8 mol/L

Step 2: Convert "V" to L

We will use the conversion factor 1 L = 1000 mL.

500 mL × 1 L/1000 mL = 0.500 L

Step 3: Calculate the moles of KBr (solute)

The molarity is the quotient between the moles of solute (n) and the liters of solution.

M = n/V

n = M × V

n = 0.8 mol/L × 0.500 L = 0.4 mol

4 0
3 years ago
Is density a chemical or physical property of a substance?
pychu [463]

Answer:

A physical property is a characteristic of a substance that can be observed or measured without changing the identity of the substance. Physical properties include color, density, hardness, and melting and boiling points. A chemical property describes the ability of a substance to undergo a specific chemical change.

I hope this helps you understand! <3

8 0
3 years ago
a. For the reaction 2H2 + 02→ 2H20, how many moles of water can be produced from 6.0 mol of oxygen? 2.0 mol b. 6.0 mol 12 mol d.
pickupchik [31]

Explanation:

from the equation 1 mole of O2 will give 2 moles of H2O then 6.0 moles of O2 will give x

6.0*2 moles/ 1 mole

= 12 moles

this implies that, 6.0 moles of O2 will give = 12 moles of water

3 0
3 years ago
Other questions:
  • Sarah and Maria mixed some iron filings with yellow sulfur powder. Both iron and sulfur are elements in the periodic table. The
    13·2 answers
  • Balance this equation please.
    13·2 answers
  • You performed the experiment using air which we know is actually a mixture of several gases. would the results of this experimen
    6·1 answer
  • If helium effuses through a porous barrier in 1.34 min, how much time (in min) would it take the same amount of ammonia to effus
    6·1 answer
  • A patient needs to be given exactly 1000ml of 15% (w/v) intravenous glucose solution. The stock solution is 35% (w/v). How many
    5·2 answers
  • What three factors affect the rate of dissolution?
    14·1 answer
  • I need help with this I attached a picture.​
    6·1 answer
  • A gaseous fluorinated methane compound has a mass of 8.00 g at 2.81 atm and 300. K in a 1.00 L container.
    6·1 answer
  • How many neutrons does be-14 have?
    7·2 answers
  • When hydrochloric acid is poured over potassium sulfide, 42.5 mL of hydrogen sulfide gas is produced at a pressure of 756 torr a
    9·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!