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
Ket [755]
3 years ago
7

Help anyone please ;) Will mark brainliest!! Thank you lol <3

Chemistry
1 answer:
tresset_1 [31]3 years ago
3 0

Answer:

20. F

21.F

22. they have different protons and that is what makes a atom different for any other atom

23.

P=9

N=10

E=9

27. 25

You might be interested in
A 25.00 ml solution of sulfuric acid H2SO4 is titrated to phenolphthalein end point with 27.00 ml of 1.700 M KOH
Nastasia [14]
<h3>Answer:</h3>

0.918 M

<h3>Explanation:</h3>

Assuming the question requires we calculate the Molarity of sulfuric acid:

We are given:

  • Volume of the acid, H₂SO₄ = 25.00 ml
  • Volume of the base, KOH = 27.00 mL
  • Molarity of the base, KOH is 1.70 M

We can calculate the molarity of the acid using the following steps;

<h3>Step 1: Write the chemical equation for the reaction.</h3>

The reaction is an example of a neutralization reaction where a base reacts with an acid to form salt and water.

Therefore, the balanced equation will be;

H₂SO₄(aq) + 2KOH(aq) → K₂SO₄(aq) + 2H₂O(l)

<h3>Step 2: Determine the moles of the base, KOH </h3>

When given molarity and the volume of a solution, the number of moles can be calculated by multiplying molarity with volume.

Number of moles = Molarity × Volume

                             = 1.700 M × 0.027 L

                              = 0.0459 moles

Thus, moles of KOH used is 0.0459 moles

<h3>Step 3: Determine the number of moles of the Acid, H₂SO₄</h3>

From the reaction, 1 mole of the acid reacts with 2 moles of KOH

Therefore, the mole ratio of H₂SO₄ to KOH is 1 : 2

Thus, moles of H₂SO₄ = Moles of KOH ÷ 2

                                     = 0.0459 moles ÷ 2

                                     = 0.02295 moles

<h3>Step 4: Calculate the molarity of the Acid </h3>

Molarity is the concentration of a solution in moles per liter

Molarity = Moles ÷ Volume

Molarity of the acid = 0.02295 moles ÷ 0.025 L

                                = 0.918 M

Thus, the molarity of the acid, H₂SO₄ is 0.918 M

5 0
3 years ago
What is the solution to the problem expressed to the correct number of significant figures?
Fed [463]

Answer:

(102 900 ÷ 12) + (170 × 1.27) = 8800

Step 1. Evaluate the expressions inside the parentheses (PEMDAS)

102 900 ÷ 12 = 8575

170 × 1.27 = 215.9

In multiplication and division problems, your answer can have no more significant figures than the number with the fewest significant figures.

Thus, the underlined digits are not significant, but we keep them in our calculator to avoid roundoff error.

Step 2. Do the addition (PEMDAS).

  8575

+    215.9

= 8790.9

Everything that you add to an insignificant digit gives an insignificant digit as an answer.

Thus, the underlined digits are not significant.

We must drop them and round up the answer to 8800.

Explanation:

8 0
3 years ago
Identify each energy exchange as primarily heat or work and determine whether the sign of ΔE is positive or negative for the sys
Semmy [17]

Answer:

a. Work, ΔE is negative;

b. Work, ΔE is negative;

c. Work, ΔE is positive.

Explanation:

In the three cases, there is energy exchange in primarily work. The heat is the energy flow because of the difference in temperature. Of course, some heat may be lost in the cases by dissipation.

In the letter <em>a</em> the system is at an initial velocity different from 0, and then it stops. The energy that is represented here is the kinetic energy, which is the energy of the movement. Note that the system goes from a higher velocity to 0, so it is losing kinetic energy, or work, so ΔE = Efinal - Einitial < 0.

In letter <em>b</em>, the system is falling from a certain high to the floor, so its gravitational potential energy is change. That potential energy represents the energy that gravity does when an object shifts vertically. Because it goes from a high to 0, the energy is been lost, so ΔE = Efinal - Einitial < 0.

In letter <em>c</em>, the system is going higher and with higher velocity, so there is a greatness in the gravitational potential energy and the kinetic energy, both works, so ΔE = Efinal - Einitial > 0.

8 0
3 years ago
If you know the mass of an object you can calculate its weight with the formula
Vikki [24]
Answer: True

The formula of weight is w = mg, where m is the mass and g is the acceleration of gravity. If you want to calculate an object's weight, you need to know the two components: mass and gravity. 

You only need to know the mass of the object because the acceleration of gravity is ALWAYS (assuming the object is on Earth) 9.8 m/s^2. 
3 0
3 years ago
For MODERATORS ONLY
MissTica

Answer:

  1. <em>The first step to becoming a Moderator is to become a Trusted Helper If you're active on Brainly and provide quality answers to help other users then you may be eligible. If you believe you qualify to become a Trusted Helper, you can apply today!</em>
  2. <em>1. A moderator ensures that the site is spam-free and has a healthy environment so that students can learn more and grow more. 2. A moderator is a very friendly person who communicates and interacts with users and clears their doubts</em>
  3. <em>An emergency is a situation that poses an immediate risk to health, life, property, or environment. ... </em>
  4. <em>990000</em>
  5. <em>Joe Biden</em>
  6. <em>Joe Biden46th U.S. President</em>
5 0
3 years ago
Other questions:
  • . Explaining How is the legislative branch organized, and<br>what are its functions?​
    5·1 answer
  • A sample of an unknown substance has a mass of 0.158 kg. If 2,510.0 J of heat is required to heat the substance from 32.0°C to 6
    15·2 answers
  • Smell of berium please answer fast
    10·1 answer
  • Titanium has an HCP crystal structure, a c/a ratio of 1.669, an atomic weight of 47.87 g/mol, and a density of 4.51 g/cm3. Compu
    9·1 answer
  • True or false organic protein catalysts are precipitates
    8·1 answer
  • Under certain conditions the rate of this reaction is zero order in ammonia with a rate constant of ·0.0038Ms−1: 2NH3(g)→N2(g)+3
    7·1 answer
  • When wave-particle duality was applied to the electron, it explained why the energy of the electron is quantized because:
    9·1 answer
  • What are the steps to balance a chemical equation?
    7·1 answer
  • Janet is studying a population of genetically-identical individuals. Janet can conclude that these organisms
    14·2 answers
  • The box in the above picture is falling from the top of a building to the ground. Two major forces are acting on the box as it f
    15·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!