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
igor_vitrenko [27]
3 years ago
12

1. Explain how and why stars appear to move through the sky throughout the night. Then, explain why Polaris does not move.

Chemistry
1 answer:
Bas_tet [7]3 years ago
3 0
Polaris the north star is very bright and it doesn’t move
You might be interested in
How much energy is required to melt 76.941g of ice
olga55 [171]

Answer:

Q=25.7 Kj

Explanation:

76.941 g H2O*1 mol/18.016= 4.27 Mol H20

(4.27 Mol H2O)(6.009 Kj/Mol)

Q=25.7 Kj

5 0
3 years ago
A piece of iron is heated to 120'C then placed in a calorimeter containing 50g of water. The water temperature is raised from 30
Lana71 [14]

Answer:

Mass of iron = 59.375 gm

Explanation:

Calories ( or joules) are added to the water by the hot steel so at the endpoint they are BOTH at 40 C

 The water gains:

     4.18  j/g-C  * 50 * (40-30 C) = 2090 j

The steel gave up 2090 j going from 120 to 40 C

2090 = .44 j/g-C  * m * (120-40)    solve fro m = 59.375 gm

3 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
What is the partial pressure of 0.50 mol Ne gas combined with 1.20 mol Kr gas at a final pressure of 730 torr?
WARRIOR [948]
  The partial pressure  of 0.50  Ne  gas    is   214.71  torr


      calculation

 the partial   pressure  of Ne  = moles  of Ne/total moles  x  final  pressure

 
find  the total  moles  of the air mixture  

that is moles of   Ne  +  moles of K=  0.50 + 1.20  =  1.70 moles
  

The partial  pressure  is therefore =   0.50 /1.70  x  730  =  214.71  torr
   
8 0
3 years ago
Read 2 more answers
Assuming equal concentrations, rank these solutions by ph.? assuming equal concentrations, rank these solutions by ph. koh (aq h
polet [3.4K]
I remember coming across this question and the options were:
KOH, HCN, NH₃, HI, Sr(OH)₂

Now, a substance with a low pH is one that dissociates completely in water to release hydrogen ions, while basic substances dissociate completely to release hydroxide ions. Therefore, in the order of increasing pH:
HI, HCN, NH₃, Sr(OH)₂, KOH
7 0
3 years ago
Other questions:
  • Can a centigram balance be read to the nearest milligram?
    12·2 answers
  • Mars is 1.52 au from the sun . about how many kilometers is mars from the sun
    9·1 answer
  • what is the specific heat capacity 82.4g of a metal that is absorbed 846 joules of heat as the temperature increases from 25c to
    5·1 answer
  • A product advertised on television claims it can "erase skin blemishes and wrinkles in 90 days or your money back." The best way
    9·2 answers
  • Why do ATP molecules store so much energy in their bonds?
    13·1 answer
  • Solid calcium oxide reacts with sulfur trioxide gas to produce solid calcium sulfate
    7·1 answer
  • In an experiment, two unknown compounds (one an alcohol and the other an ether) of equal molecular mass were dissolved in water.
    9·2 answers
  • Which of the following representations shows how one variable changes in response to another variable?
    15·2 answers
  • A sample of hydrogen gas at a pressure of 977 mm Hg and a temperature of 32 °C, occupies a volume of 11.3 liters. If the gas is
    9·1 answer
  • Compared to rodents, rabbits have an extra pair of incisors and other skeletal structures that are different. They also have som
    8·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!