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
madreJ [45]
2 years ago
11

HELP ASAP! I will give brainiest if you answer all questions correctly.

Chemistry
2 answers:
oksano4ka [1.4K]2 years ago
4 0

Answer:

28) -88kj

29) 300kj

30) -204kj

DaniilM [7]2 years ago
4 0

Answer:

28). 261

29). 788

30).-6201

Explanation:

I just took lesson and it said those were correct, I added screenshots of the lesson if you need it :)

You might be interested in
Which best describes the motion of pentane molecules in liquid phase?
Ganezh [65]
Hydrocarbons may vary from state to state depending on the length of the carbon chain. For methane to butane, they are usually in gas form. Starting from pentane, they are in the liquid form. For very long carbon chains, that occur as solids. Now, it depends if the pentane is in a nonpolar liquid or polar liquid. Since pentane is nonpolar, it is miscible in the liquid solvent. The movements would most likely be free flowing. But if he solvent is polar, the molecules would repel with one another. In the end, it will form two liquid phases, on for the pentane and one for the polar solvent.
3 0
2 years ago
Part B: Copper (II) chloride (CuCl2; 0.98g) was dissolved in water and a piece of aluminum wire (Al; 0.56g) was placed in the so
babymother [125]

.,. .................

7 0
2 years ago
Latent heat of vaporization is used to (1 Point) (a) overcome the forces of attraction between molecules in solid-state. (b) inc
Reil [10]

Answer:

Not sure what the answer is

Explanation:

I did this a while ago and dont remember sorry

4 0
2 years ago
A line in the Brackett series of hydrogen has a wavelength of 1945 nm. From what state did the electron originate?
fiasKO [112]
Rydberg Eqn is given as:
 1/λ = R [1/n1^2 - 1/n2^2] 
<span>Where λ is the wavelength of the light; 2626 nm = 2.626×10^-6 m </span>
<span>R is the Rydberg constant: R = 1.09737×10^7 m-1 </span>
<span>From Brackett series n1 = 4 </span>
<span>Hence 1/(2.626×10^-6 ) = 1.09737× 10^7 [1/4^2 – 1/n2^2] </span>
<span>Some rearranging and collecting up terms: </span>
<span>1 = (2.626×10^-6)×(1.09737× 10^7)[1/16 -1/n2^2] </span>
<span>1= 28.82[1/16 – 1/n2^2] </span>
<span>28.82/n^2 = 1.8011 – 1 = 0.8011 </span>
<span>n^2 = 28.82/0.8011 = 35.98 </span>
<span>n = √(35.98) = 6</span>
4 0
2 years ago
Read 2 more answers
Find the age t of a sample, if the total mass of carbon in the sample is mc, the activity of the sample is a, the current ratio
Paha777 [63]
N₀ is the number of C-14 atoms per kg of carbon in the original sample at time = Os when its carbon was of the same kind as that present in the atmosphere today. After time ts, due to radioactive decay, the number of C-14 atoms per kg of carbon is the same sample which has decreased to N. λ is the radioactive decay constant.
Therefore N = N₀e-λt which is the radioactive decay equation,
N₀/N = eλt In (N₀.N= λt. This is the equation 1
The mass of carbon which is present in the sample os mc kg. So the sample has a radioactivity of A/mc decay is/kg. r is the mass of C-14 in original sample at t= 0 per total mass of carbon in a sample which is equal to [(total number of C-14 atoms in the sample at t m=m 0) × ma]/ total mass of carbon in the sample.
Now that the total number of C-14 atoms in the sample at t= 0/ total mass of carbon in sample = N₀ then r = N₀×ma
So N₀ = r/ma. this equation 2.
 The activity of the radioactive substance is directly proportional to the number of atoms present at the time.
Activity = A number of decays/ sec = dN/dt = λ(number of atoms of C-14 present at time t) = 
λ₁(N×mc). By rearranging we get N = A/(λmc) this is equation 3.
By plugging in equation 2 and 3 and solve t to get
t = 1/λ In (rλmc/m₀A).

6 0
2 years ago
Other questions:
  • Elements that can be described by the hardness shininess and ductility
    9·1 answer
  • Why would it be better to be an r-selected species if the water resources in an area were to become more limited over a short pe
    8·2 answers
  • How many moles of ions are in 285 ml of 0.0150 m mgcl2?
    10·2 answers
  • What is the empirical formula of a compound containing 90 grams carbon, 11 grams hydrogen, and 35 grams nitrogen? A. C3H4N B. C2
    6·1 answer
  • Identify the type of solid from the description. Select from the following choices: metallic solid, network solid, molecular sol
    5·1 answer
  • A reaction A(aq)+B(aq)↽−−⇀C(aq) has a standard free‑energy change of −4.20 kJ/mol at 25 °C. What are the concentrations of A, B,
    8·1 answer
  • What is the best example of a cyclic event?
    7·1 answer
  • White phosphorus (P4) is used to produce phosphorus oxides, such as P4O10. How many kilograms of P4O10 would be produced from 41
    7·1 answer
  • During a titration the following data were collected. A 50.0 mL portion of an HCl solution was titrated with 0.500 M NaOH; 200.
    7·1 answer
  • Determine the percent yield for the reaction
    5·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!