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
Likurg_2 [28]
3 years ago
15

Which statement is correct?

Chemistry
1 answer:
rosijanka [135]3 years ago
4 0

Answer:

B. Chemical changes produce new substances; physical changes do not.

Explanation:

Physical changes only alter appearances, while chemical changes are interactions that create new chemical formulas.

You might be interested in
Hydrogen iodide, HI, is formed in an equilibrium reaction when gaseous hydrogen and iodine gas are heated together. If 20.0 g of
Kaylis [27]

Answer: D. 19.9 g hydrogen remains.

Explanation:

To calculate the moles, we use the equation:

\text{Number of moles}=\frac{\text{Given mass}}{\text {Molar mass}}

a) moles of H_2

\text{Number of moles}=\frac{20.0g}{2g/mol}=10.0moles

b) moles of I_2

\text{Number of moles}=\frac{20.0g}{254g/mol}=0.0787moles

H_2(g)+I_2(g)\rightarrow 2HI(g)

According to stoichiometry :

1 mole of I_2 require 1 mole of H_2

Thus 0.0787 moles of l_2 require=\frac{1}{1}\times 0.0787=0.0787moles of H_2

Thus l_2 is the limiting reagent as it limits the formation of product and H_2 acts as the excess reagent. (10.0-0.0787)= 9.92 moles of H_2are left unreacted.

Mass of H_2=moles\times {\text {Molar mass}}=9.92moles\times 2.01g/mol=19.9g

Thus 19.9 g of H_2 remains unreacted.

5 0
3 years ago
An element in group 7 on the periodic table most likely has which physical property?
larisa86 [58]

Answer:

They are most likely solid

Explanation:

solid is a physical property

3 0
3 years ago
Students find the pH of Substance A to be 2.1 and Substance B to be 4.4. They are told Substance C is less acidic than Substance
Slav-nsk [51]

Answer:

the range should be 2.2 to 4.3

Explanation:

I think so because the numbers at the left side of the scale from 1 are more acidic so as it increases it's still acidic but lesser so 1 is more acidic than 2 so I used 2.2 as the beginning of the range because it's less acidic than A even though its a greater number and 4.3 is lesser than 4.4 but its still greater on the scale. frankly speaking I don't feel so correct because it's in decimal so try and compare facts thank you

8 0
3 years ago
Magnesium and copper react with dilute acids to make salts and hydrogen gas<br> True<br> False
omeli [17]

Answer:

True

Explanation:

magnesium and copper react with dilute acids to make salts and hydrogen gas

5 0
3 years ago
1. Describe the evidence that stress plays a role in the development of schizophrenia.
valentina_108 [34]

Answer:

Research shows that patients with schizophrenia are more affected by stress physically as well as emotionally, for instance they show different changes in heart rate under stress and a greater overall risk of cardiovascular disease.

Explanation:

8 0
3 years ago
Other questions:
  • For the chemical reaction CaI2+2AgNO3-&gt; 2AgI+Ca(NO3)2 how many moles of silver iodide will be produced from 205g of calcium i
    7·1 answer
  • What is the wavelength (in meters) of an electromagnetic wave whose frequency is 2.63 × 1012 s−1?
    9·1 answer
  • What happens if you consume bleach?
    6·1 answer
  • Why is the brcl molecules polar??
    7·2 answers
  • Two students were in Chemistry Class completing an assigned lab experiment. The two students were to mix 5.34g CaCl2 with CuSO4
    5·1 answer
  • The number main-group elements'valance electrons can be determined by____ on the periodic table​
    6·1 answer
  • 1. List 3 physical and chemical phenomena
    9·1 answer
  • ATOMS, help me with this, and thank you for your help
    9·2 answers
  • Which picture is showing the correct direction of the wind?
    11·1 answer
  • Explain the trend as you move across a row of the periodic table for each of the following atomic
    11·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!