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
dezoksy [38]
3 years ago
8

water has a specific heat of 4.18 j/gK and a molar heat of vaporization of 40.7 kJ. Calculate the minimum amount of heat necessa

ry to vaporize 90 g of water starting at 20 c
Chemistry
1 answer:
Marrrta [24]3 years ago
5 0

Answer:

To calculate the minimum amount of heat necessary to vaporize 90 g of water starting at 20 c

Explanation:

We will use heat balance equation

Q = q1+q2 = mCΔt + nL

where

m = mass of water = 90g

C = specifi heat of water =4.18J/gK

L = Latent heat of Vaporization = 40.7kJ/mol

Δt = temperature changes = 100 - 20 = 80 degree

water at 20 degrees to water at 100 degrees

then water at 100 degrees to vapor at 100 degrees

q1 = (90g)(4.18J/gK)(80K)

q1 = 30096J=30.1kJ

But

m =90 g water, gives  n = 5mol water (divide by his molar mass which is 18g)

q2=nL= (40.7kJ/mol)(5mol)

q2=203.5kJ

the minimum amount of heat necessary to vaporize 90 g of water starting at 20 c = q1+q2 =30.1+203.5=233.6kJ

You might be interested in
Can you help me with these questions?
ZanzabumX [31]
1.) C. Microwave, visible, gamma
4.) B. I’m pretty sure frequency increases from left to right and wavelength gets shorter

1.) A. Atomic bomb
2.) C. GPS
3.) A. FM radio
4.) B. Radar detector

It’s been like 2-3 years since I’ve done this stuff so I’m not entirely sure‍♀️
7 0
3 years ago
Phosphine (PH3) can be prepared by the reaction of calcium phosphide , Ca3P2: based on this equation : Ca3P2 + 6H2O —-> 3 Ca(
MrMuchimi

Taking into account the reaction stoichiometry, you can observe that:

  • one mole of Ca₃P₂ produces 2 mol of PH₃.
  • the mole ratio between phosphine and calcium phosphide is 2 mol PH₃ over 1 mol Ca₃P₂.

<h3>Reaction stoichiometry</h3>

In first place, the balanced reaction is:

Ca₃P₂ + 6 H₂O  → 3 Ca(OH)₂ + 2 PH₃

By reaction stoichiometry (that is, the relationship between the amount of reagents and products in a chemical reaction), the following amounts of moles of each compound participate in the reaction:

  • Ca₃P₂:1 mole
  • H₂O: 6 moles
  • Ca(OH)₂: 3 moles
  • PH₃: 2 moles

The molar mass of the compounds is:

  • Ca₃P₂: 182 g/mole
  • H₂O: 18 g/mole
  • Ca(OH)₂: 74 g/mole
  • PH₃: 34 g/mole

Then, by reaction stoichiometry, the following mass quantities of each compound participate in the reaction:

  • Ca₃P₂: 1 mole ×182 g/mole= 182 grams
  • H₂O: 6 moles× 18 g/mole= 108 grams
  • Ca(OH)₂: 3 moles ×74 g/mole= 222 grams
  • PH₃: 2 moles ×34 g/mole= 68 grams

<h3>Correct statements</h3>

Then, by reaction stoichiometry, you can observe that:

  • one mole of Ca₃P₂ produces 2 mol of PH₃.
  • the mole ratio between phosphine and calcium phosphide is 2 mol PH₃ over 1 mol Ca₃P₂.

Learn more about the reaction stoichiometry:

<u>brainly.com/question/24741074</u>

<u>brainly.com/question/24653699</u>

4 0
2 years ago
Which of the following is not equal 225 g?
vekshin1
G to dkg is 1 place to the right, move the decimal point 1 place to the left 
<span>225 g = 22.5 dkg 
C is the answer</span>
3 0
3 years ago
Read 2 more answers
What mass of CaSO3 must have been present initially to produce 14.5 L of SO2 gas at a temperature of 12.5°C and a pressure of 1.
german
When the reaction equation is:

CaSO3(s) → CaO(s) + SO2(g)

we can see that the molar ratio between CaSO3 & SO2 is 1:1 so, we need to find first the moles SO2.

to get the moles of SO2 we are going to use the ideal gas equation:

PV = nRT

when P is the pressure =  1.1 atm

and V is the volume = 14.5 L 

n is the moles' number (which we need to calculate)

R ideal gas constant = 0.0821

and T is the temperature in Kelvin = 12.5 + 273 = 285.5 K

so, by substitution:

1.1 * 14.5 L = n * 0.0821 * 285.5

∴ n = 1.1 * 14.5 / (0.0821*285.5)

       = 0.68 moles SO2

∴ moles CaSO3 = 0.68 moles

so we can easily get the mass of CaSO3:

when mass = moles * molar mass

and we know that the molar mass of CaSO3= 40 + 32 + 16 * 3 = 120 g/mol


∴ mass = 0.68 moles* 120 g/mol = 81.6 g
7 0
3 years ago
An isotope contains 16 protons 18 electrons and 16 neutrons. what is the identity of the isotope
jarptica [38.1K]

Answer:

Sulfur

Explanation:

You find the identity by looking at the number of protons.  The number of protons never change for an element.

3 0
3 years ago
Other questions:
  • You are using a new type of metal to make electrical wires. What element would you consider using to do this ? *
    12·2 answers
  • 5. Sodium peroxide reacts vigorously with water in the following unbalanced equation:
    5·1 answer
  • Can someone help me solve this? I was given the answer at the end of class but I don't understand how the teacher got it. (Direc
    8·1 answer
  • Define: Law of Definite Proportion
    7·1 answer
  • Explain how you can predict the products of a simple chemical reaction based on the outermost electron state of atoms, trends in
    15·1 answer
  • How many kilojoules of heat are produced when 34.0 g of Fe2O3 reacts with an excess of
    13·1 answer
  • Solids are not Fluids because ?
    9·2 answers
  • The law of partial pressures was developed by ___________.
    7·1 answer
  • What is the pressure exerted by a force of 15.0 N over an area of 0.00372 m^2 ?
    12·1 answer
  • How would you measure the melting point of a solid that melts above 100.
    14·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!