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
Leviafan [203]
3 years ago
11

A friend tells you, because composition does not change during a physical changes, the appearance of a substance does not change

. is your friend correct? explain why.
Chemistry
1 answer:
Travka [436]3 years ago
3 0
That friend is not correct. Physical change is characterized by a change in appearance without any change in composition. So, if the appearance did not change in the situation, then there is no change in the system. This type of change affects the form of a substance but not the composition or the structure of the molecules. Examples of this type of change are ice melting, cutting a paper into half, clay is molded to a new shape, butter melting, water evaporating. The change that involves a change in chemical composition is classified a chemical change. In this type of change, chemical reactions would take place.
You might be interested in
A tank of oxygen has a volume of 1650 L. The temperature of the gas inside is 35?C. If there are 9750 moles of oxygen in the tan
Paul [167]

Answer:

2192.64 PSI.

Explanation:

  • From the general law of ideal gases:

<em>PV = nRT.</em>

where, P is the pressure of the gas in atm.

V is the volume of the container in L (V = 1650 L).

n is the no. of moles of the gas in mol (n = 9750 mol).

R is the general gas constant (R = 0.082 L.atm/mol.K).

T is the temperature of the gas in (T = 35°C + 273 = 308 K).

∴ P = nRT/V = (9750 mol)(0.082 L.atm/mol.K)(308 K)/(1650 L) = 149.2 atm.

  • <u><em>To convert from atm to PSI:</em></u>

1 atm = 14.696 PSI.

<em>∴ P = 149.2 atm x (14.696 PSI/1.0 atm) = 2192.64 PSI.</em>

4 0
3 years ago
A solution contains 90 milliequivalents of HC1 in 450ml. What is its normality?
Rashid [163]

Answer:

Normality N = 0.2 N

Explanation:

Normality is the number of gram of equivalent of solute divided of volume of solution, where the number of gram of equivalent of solute is weight of the solute divided by the equivalent weight.

Normality is represented by N.

Mathematically, we have :

\mathbf{Normality \ N = \dfrac{Number \ of \ gram \of \ equivalent\  of\  solute }{volume \ of \ solution}}

Given that:

number of gram of equivalent of solute = 90 milliequivalents 90 × 10⁻³ equivalent

volume of solution (HCl) = 450 mL 450 × 10⁻³ L

\mathbf{Normality \ N = \dfrac{90 \times 10^{-3}}{450 \times 10^{-3}}}

Normality N = 0.2 N

7 0
3 years ago
Which statement best describes the building?
Kamila [148]

Answer:

the answer is A

Explanation:

because abiotic things are non-living things

7 0
3 years ago
Read 2 more answers
What is the theoretical yield of fluorenone if you oxidize 175 mg of fluorene?
My name is Ann [436]

Answer:

  • 602 mg of CO₂ and 94.8 mg of H₂O

Explanation:

The<em> yield</em> is measured by the amount of each product produced by the reaction.

The chemical formula of <em>fluorene</em> is C₁₃H₁₀, and its molar mass is 166.223 g/mol.

The <em>oxidation</em>, also know as combustion, of this hydrocarbon is represented by the following balanced chemical equation:

        2C_{13}H_{10}+31O_2\rightarrow 26CO_2+10H_2O

To calculate the yield follow these steps:

<u>1. Mole ratio</u>

          2molC_{13}H_{10}:31molO_2:26molCO_2:10molH_2O

<u />

<u>2. Convert 175mg of fluorene to number of moles</u>

  • 175mg/times 1g/1,000mg=0.175g

  • Number of moles = mass in grams / molar mass

  • \text{number of moles}=0.175g/166.223g/mol=0.0010528mol

<u>3. Set a proportion for each product of the reaction</u>

a) <u>For CO₂</u>

i) number of moles

         2molC_{10}H_{13}/26molCO_2=0.0010528molC_{10}H{13}/x

x=0.0010528molC_{10}H_{13}\times 26molCO_2/2molC_{10}H_{13}=0.013686molCO_2

ii) mass in grams

The molar mass of CO₂ is 44.01g/mol

  • mass = number of moles × molar mass
  • mass = 0.013686 moles × 44.01 g/mol = 0.602 g = 602mg

b) <u>For H₂O</u>

i) number of moles

0.0010528molC_{10}H_{13}\times10molH_2O/2molC_{10}H_{13}=0.00526molH_2O

ii) mass in grams

The molar mass of H₂O is 18.015g/mol

  • mass = number of moles × molar mass
  • mass = 0.00526 moles × 18.015 g/mol = 0.0948mg = 94.8 mg
4 0
3 years ago
Give an example of a specialized cell.
Gre4nikov [31]

Answer:

Muscle cell

Explanation:

An example of a specialized cell would be a muscle cell, which allows muscles to contract. A specialized cell has a specific function.

4 0
2 years ago
Read 2 more answers
Other questions:
  • Which example best shows conservation of resources?
    5·2 answers
  • What element in the second period has the largest atomic radius?
    6·1 answer
  • An excess of hydrogen ions in the body fluids can have fatal results because this can
    6·1 answer
  • An ideal sample weighing 1.28g at 127C (temp) and 1 atm has a volume of 0.250L. Determine the molar mass of the gas.
    9·1 answer
  • Water (10 kg/s) at 1 bar pressure and 50 C is pumped isothermally to 10 bar. What is the pump work? (Use the steam tables.) -7.3
    10·1 answer
  • a. Calculate the pH of a solution that has [H3O+]= 4.3 x 10-5 M. b. Is the solution acidic or basic? How do you know?
    14·1 answer
  • A car is traveling with an initial velocity of 15 m/s when the driver decides to go faster by accelerating at 5 m/s2 for 10 seco
    8·1 answer
  • A dodder plant wraps itself around a potato plant. The dodder then uses its root system to obtain water and nutrients from the p
    7·2 answers
  • Commercial agriculture can often lead to water-quality problems. In one to two sentences, explain how two of those problems occu
    14·1 answer
  • Who is Harry Styles?
    7·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!