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
evablogger [386]
2 years ago
9

What do all of these things have in common? ______________________________ Bird, dog, tree, person, flower, grass, bacteria, cat

Chemistry
1 answer:
olga2289 [7]2 years ago
5 0
They are all part of the biosphere?
You might be interested in
C2H5OH(l) + 3O2(g) → 2CO2(g) + 3H2O(l), ΔH = –1.37 × 103 kJ For the combustion of ethyl alcohol as described in the above equati
hammer [34]

Answer:

The true statements are: I. The reaction is exothermic.

II. The enthalpy change would be different if gaseous water was produced.

Explanation:

The given chemical reaction: C₂H₅OH(l) + 3O₂(g) → 2CO₂(g) + 3H₂O(l),  ΔH= -1.37×10³kJ

1. In an exothermic reaction, heat or energy is released from the system to the surrounding. Thus for an exothermic process the change in enthalpy is less than 0 or negative (ΔH < 0) .

Since the enthalpy change for a combustion reaction is negative. <u>Therefore, the given reaction is exothermic.</u>

2. The change in enthalpy (ΔH) of a reaction is equal to difference of the sum of standard enthalpy of formation (ΔHf°) of the products and the reactants.

ΔHr° = ∑ n.ΔHf°(products) − ∑ n.ΔHf°(reactants)

As the value of ΔHf° of water in gaseous state and liquid state is not the same.

<u>Therefore, the enthalpy change of the reaction will be different, if gaseous water was present instead of liquid water.</u>

3. An oxidation-reduction reaction or a redox reaction involves simultaneous reduction and oxidation processes.

The given chemical reaction, represents the combustion reaction of ethanol.

Since combustion reactions are redox reactions. <u>Therefore, the given combustion reaction is an oxidation-reduction reaction.</u>

4. According to the ideal gas equation: P.V =n.R.T

Volume (V) ∝ n (number of moles of gas)

Since the number of moles (n) of gaseous reactants is 3 and number of moles of gaseous (n) products is 2.

<u>Therefore, the volume occupied by 3 moles of the reactant gaseous molecules will be more than 2 moles product gaseous molecules.</u>

5 0
3 years ago
An object has a mass of 20 kg and a volume of 5 mL. What is the object's density?
e-lub [12.9K]
Good grief, this stuff got caught in a black hole somewhere. It is terribly dense.
1 mL = 1 cc under normal conditions.

d = mass / volume
m = 20 kg
v = 5 mL

d = 20kg / 5 mL
d = 4 kg / mL
d = 4 kg / cc

A <<<<answer
7 0
3 years ago
Read 2 more answers
What do all codes such as morse and brallie have in common
astra-53 [7]

Answer: Morse code and Braille use representations to form messages.

Explanation:

- they both have military roots.

-also a similarity is that braille letters are made of 1 to 6 dots, and Morse code is also made of 1 to 6 dots and dashes

-

4 0
3 years ago
Pls answer ill give brainliest question in pic
RUDIKE [14]
C, im pretty sure if im wrong my bad
6 0
2 years ago
Which of these is an example of a physical change? A) iron melting B) steel rusting C) paper burning Eliminate D) wood decaying
ludmilkaskok [199]
A) iron melting is the only example of physical change, because it's just a change of state (from solid to liquid).
The others, rusting, combustion, and decay are all chemical changes, because it will result in changing the chemical bonds between the atoms.
7 0
3 years ago
Read 2 more answers
Other questions:
  • Match each type of chemical bond with its properties. Drag the items
    11·1 answer
  • Who was on the grand committee
    7·1 answer
  • 6.75 L of carbon dioxide gas are stored at a pressure of 175 atm. If the temperature and number of gas particles do not change,
    5·1 answer
  • The air helps regulate Earth's atmosphere so that
    8·1 answer
  • Al calentar la mantequilla, esta se transforma en liquido, este cambio se denomina?
    5·1 answer
  • Aluminum reacts with chlorine gas to form aluminum chloride
    15·1 answer
  • What is the [H ] of a solution of 0.001 M aqueous sulfuric acid (H2SO4) is H2SO4 ionizes in water according to the balanced chem
    12·1 answer
  • Could someone help me!<br><br> Consider a cup made of plastic. What are the pros of using plastic?
    6·1 answer
  • • What is produced at the end of the cell cycle? How do they compare to each other and
    8·1 answer
  • A compound with the empirical formula CH2 was found to have a molar mass of approximately 112 g. Write the molecular formula of
    7·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!