4.3 x 10^2 - 7.0 x 10^2 in scientific notation

Answers

Answer 1
-2.7 × 10^2 is the result of the equation.

Related Questions

How many molecules of ethanol, C2H5OH, are contained in a 150. gram sample?
1.96 x 1024
46.0
6.02 x 1023
5.1 x 10-25

Answers

Answer:

1.96 × 10²⁴ molecules

Explanation:

Step 1: Given data

Mass of ethanol (m): 150. g

Step 2: Calculate the number of moles (n) corresponding to 150. g of ethanol

The molar mass of ethanol is 46.07 g/mol.

150. g × 1 mol/46.07 g = 3.26 mol

Step 3: Calculate the number of molecules in 3.26 moles of ethanol

To convert moles into molecules, we need Avogadro's number: there are 6.02 × 10²³ molecules in 1  mole of molecules.

3.26 mol × 6.02 × 10²³ molecules/1  mol = 1.96 × 10²⁴ molecules

What is the H+ concentration of a substance with a pH of 5?

Answers

Answer:

- log{H+ }= - log {5}= -0.6990

An increase in temperature will cause an increase in diffusion rate because Multiple Choice hot molecules get smaller and therefore diffuse faster. the frequency and force of molecular collisions decreases. hot water changes to a solid, so diffusion is easier. hot water is thinner than cold water. the frequency and force of molecular collisions increases.

Answers

Answer:

hot water is thinner than cold water.

Explanation:

The rate of diffusion of a substance has a lot to do with the temperature of a body.

Let us take water for instance, cold water has a greater density than hot water. As a result of this, the molecules in cold water are slower when in motion and more sluggish.

On the other hand, the molecules of hot water are quite faster since hot water has a lower density(thinner than cold water).

Thus, an  increase in temperature will cause an increase in diffusion rate because hot water is thinner than cold water.

Calculate the volume of sulfur dioxide produced when 27.9 mL O2 reacts with carbon disulfide.

Answers

Answer:

18.6 ml

Explanation:

From the balanced equation given:

Volume of oxygen = 27.9 mL

From the equation, we will see that three moles of oxygen react with CS_2 to give two moles of sulfur dioxide (SO_2)

Also, three mL of O_2 yields two mL of SO_2

Now, to calculate the volume of SO_2; we have:

[tex]=27.9 mL \times \dfrac{2 mL \ of SO_2}{3 mL \ O_2}[/tex]

= 18.6 mL of SO_2

PLEASE NO BOTS lol
Ethyne or acetylene is also used in cutting torches. The acetylene is combined with pure oxygen producing a flame with a temperature of 6332 °F or 3500 °C. The combustion of acetylene in the presence of excess oxygen yields carbon dioxide and water:

2C2H2 (g) + 5O2 (g) --> 4CO2 (g) + 2H2O (l)

Calculate the value of ΔS° for this reaction.


A. +689.3 J/mol K

B. +432.4 J/mol K

C. -432.4 J/mol K

D. -122.3 J/mol K

Answers

The correct answer is

C. -432.4 J/mol K

is chemistry hard in grade 11
explain to me everything plsss thanks ​

Answers

Explanation:

Chemistry is overall a very interesting subject and it really depends on what you personally consider enjoyable. I love chemistry and I think that grade 11 chemistry is very easy. It's mostly based on balancing chemical equation, molar mass calculations and more. But it's a great course to take based on my experience.

Qué uso le darías en la vida diaria ayuda

Answers

Answer:

ako po kailangan ko po nga ayuda

Explanation:

thanks for the points ❤️

LPLEASE HELP I AM STUCK I. THIS Q

Answers

Answer:

c

Explanation:

do carbon has ions charge?​

Answers

Carbon has an outer shell consisting of 4 valence electrons. ... Thus, a carbon ion can have a charge of anywhere from -4 to +4, depending on if it loses or gains electrons. Although the most common oxidation states of carbon are +4 and +2, carbon is able to make ions with oxidation states of +3, +1, -1, -2, and -3.

A scientist wants to investigate several problems. In which of the following situations is using a simulation LEAST suitable for solving a problem?
a. When a scientific study requires performing a large number of trials that need to be conducted very quickly
b. When the solution to the problem requires real-world data inputs that are continually measured at regular intervals.
c. When performing an experiment that would be too costly or dangerous to conduct in the real world
d. When it is considered acceptable to make simplifying assumptions when modeling a real-world object or phenomenon

Answers

Answer:

A

Explanation:

got from another website

The simulation which is least suitable to scientists for solving a problem is when performing an experiment that would be too costly or dangerous to conduct in the real world.

What is scientific approach?

Scientific approach is an empirical method of acquiring knowledge and result. This method involved the careful observation of the problem, applying skepticism about the problem and giving cognitive assumptions also.

If a scientist wants to investigate several problems, then they will perform a large no. of trials at regular intervals to get the required result. But if performing of any experiment is dangerous to conduct in the real world then scientists will ignore to solve that problem.

Hence, option (C) is correct.

To know more about scientific approach, visit the below ink:

https://brainly.com/question/497944

What mass of aluminum sulfate is required to precipitate all of the Ba?? out of 45.0 mL of 0.548 M barium nitrate solution? 3 Ba(NO3)2 (aq) + Al2(SO4)3 (aq) --> 3 BaSO2 (s) + 2 Al(NO3)3 (aq) ​

Answers

Answer:

2.82 g

Explanation:

Step 1: Write the balanced precipitation reaction

3 Ba(NO₃)₂ (aq) + Al₂(SO₄)₃ (aq) ⇒ 3 BaSO₄(s) + 2 Al(NO₃)₃(aq)

Step 2: Calculate the reacting moles of Ba(NO₃)₂

45.0 mL (0.0450 L) of 0.548 M Ba(NO₃)₂ react.

0.0450 L × 0.548 mol/L = 0.0247 mol

Step 3: Calculate the moles of Al₂(SO₄)₃ that react with 0.0247 moles of Ba(NO₃)₂

The molar ratio of Ba(NO₃)₂ to Al₂(SO₄)₃ is 3:1. The reacting moles of Al₂(SO₄)₃ are 1/3 × 0.0247 mol = 8.23 × 10⁻³ mol

Step 4: Calculate the mass corresponding to 8.23 × 10⁻³ moles of Al₂(SO₄)₃

The molar mass of Al₂(SO₄)₃ is 342.2 g/mol.

8.23 × 10⁻³ mol × 342.2 g/mol = 2.82 g

What is the Molar mass of zinc

Answers

Answer:

65.38 u

Explanation:

hope this helps you out!!!!!!!

They Mean D and not U H just took the test and its D i hope this help

(NH4)2Cr2O7 Cr2O3 + N2 + H2O
If 4.7369 moles of H2O are produced, how many moles of (NH4)2Cr2O7 were reacted?

Answers

Answer:

the original substances in any chemical reaction. products. the resulting substances in any....chromium(III) oxide, and water. (NH4)2Cr2O7(s) → N2(g) + Cr2O3(s) + 4H2O(g).

8. Sulfur has a first ionization energy of 1000 kJ/mol. Photons of what frequency are required to ionize one mole of Sulfur?​

Answers

Answer:

the frequency of photons [tex]v = 1.509\times10^{39}Hz[/tex]

Explanation:

Given:  first ionization energy of 1000 kJ/mol.

No. of moles of sulfur = 1 mole

[tex]\Delta E_1 = 1000KJ/mol[/tex]

We know that plank's constant

[tex]h = 6.626\times10^{-34} Js[/tex]

Let the frequency of photons be ν

Also we know that ΔE = hν

this implies ν = ΔE/h

[tex]= \frac{10^6J}{6.626\times10^{-34} Js}[/tex]

[tex]v = 1.509\times10^{39}Hz[/tex]

Hence, the frequency of photons [tex]v = 1.509\times10^{39}Hz[/tex]

How many atoms are there in 24 moles of Fe?

Answers

Answer: There are [tex]145 \times 10^{23}[/tex] atoms in 24 moles of Fe.

Explanation:

According to the mole concept, 1 mole of a substance contains [tex]6.022 \times 10^{23}[/tex] atoms.

Therefore, atoms present in 24 moles of Fe are calculated as follows.

[tex]24 mol \times 6.022 \times 10^{23} atoms/mol\\= 144.52 \times 10^{23} atoms\\or, 145 \times 10^{23} atoms[/tex]

Thus, we can conclude that there are [tex]145 \times 10^{23}[/tex] atoms in 24 moles of Fe.

A sample was then prepared containing 14.00 mL of coffee and 8.00 mL of 4.80 ppm Li , and diluted to a 50.00 mL total volume. The ratio of the internal standard signal to the analyte signal in the unknown sample was found to be 0.840/1.000 (Li signal/Na signal). Determine the unknown concentration of Na in the coffee sample.

Answers

Answer:

The right answer is "[tex][Na^+]=5.57 \ ppm[/tex]".

Explanation:

The given values are:

[tex]\frac{A_s}{A_{coffee}} =\frac{0.840}{1.000}[/tex]

According to the question,

The concentration of standard will be:

=  [tex]\frac{7.80}{50.00}\times 4.80[/tex]

=  [tex]0.156\times 4.80[/tex]

=  [tex]0.748 \ ppm[/tex]

Coffee after dilution,

⇒  [tex]\frac{A_{coffee}}{C_{coffee}} =F\times \frac{A_s}{C_s}[/tex]

or,

⇒  [tex]C_{coffee}=\frac{A_{coffee}}{A_s}\times \frac{C_s}{F}[/tex]

On substituting the values, we get

⇒               [tex]=\frac{1.000}{0.840}\times \frac{0.748}{1.68}[/tex]

⇒               [tex]=1.191\times 1.3104[/tex]

⇒               [tex]=1.561 \ ppm[/tex]

hence,

In unknown sample, the concentration of coffee will be:

=  [tex]1.561\times \frac{50}{14}[/tex]

=  [tex]\frac{78.05}{14}[/tex]

=  [tex]5.57 \ ppm[/tex]

The ΔHfus for ethanol is 4.60 kJ/mol. If it takes 7500.0 Joules of energy to melt a sample of ethanol, how many grams of ethanol are in the sample? The chemical formula for ethanol is C2H5OH.

Answers

Answer:

Explanation:

Determine the number of moles in 1.5 x 10^25
atoms of iron.

Answers

It should be 20 moles of iron

Convert 61 μg of aluminum phosphate to grams. (Hint: 1 μg = 1 x 10-6 g, so multiply 61 by 1 x 10-6)

Answers

Answer: 61 μg of aluminum phosphate in grams is equal to [tex]61 \times 10^{-6} g[/tex].

Explanation:

According to standard conversion of units, 1 microgram [tex](\mu g)[/tex] is equal to [tex]1 \times 10^{-6}[/tex] g.

Therefore, [tex]61 \mu g[/tex] is converted into grams as follows.

[tex]1 \mu g = 10^{-6} g\\61 \mu g = 61 \mu g \times \frac{10^{-6}}{1 g}\\= 61 \times 10^{-6} g[/tex]

Thus, we can conclude that 61 μg of aluminum phosphate in grams is equal to [tex]61 \times 10^{-6} g[/tex].

someone help me with this please, it’s overdue:(

Answers

Answer:

See explanation.

Explanation:

Hello there!

3. In this case, according to the given question, it turns out possible for us to say that any chemical formula, for an ionic compound, has the cation (positive) on the left and the anion (negative) on the right; thus, since Mg is a metal, which tends to lose electrons and become positively charged whereas the Cl is a nonmetal, which tends to gain electrons and become negatively charged, we have the following:

[tex]Mg^{2+}Cl^-\\\\Mg^{2+}Cl^-_2\\\\MgCl_2[/tex]

4. In this case, since lithium is a metal, as well as magnesium, it is not possible for them to switch around their charges as they will not be bonded because they will be repelled rather than attracted because of their equal positive charges.

Regards!

Jasmine travels a lot and collects rocks wherever she goes. She was examining two rocks from her collection, and she noticed that they are different types of rock. How could energy have played a role in the different rock types forming?


A. Energy changes rock on different continents in different ways. Each continent on Earth has different rock that might form liquid rock or small rock pieces when exposed to energy.


B. Energy caused one rock type to form, but not the other. Rock that forms because of energy is a different type of rock than rock that forms without energy.


C. Energy from different sources leads to different types of rock. Energy inside Earth melts rock into liquid rock, but energy from the sun causes rock to weather into small pieces of rock.


D. Energy causes different types of rock to change in different ways. Energy changes igneous rock into liquid rock and changes sedimentary rock into small pieces of rock.

Answers

Answer:

C

Explanation:

energy from different sources leads to different types of rocks. energy inside the earth(volcanoes) melts rocks into liquid rock(molten larva) but energy from the sun(heat radiation) causes rock to weather(breakdown) into small pieces of rocks

How many moles of KOH are present in 750. mL of a 0.250 M solution?

Answers

Answer:

Answer: Number of moles of KOH present in solution is 3.75.

Explanation:

0.1 moles

There are 0.1 moles of solute in 250 mL of 0.4 M solution.

1 Answer. 1 mol of NaOH

A catalyst is:

a chemical found in leaves
a chemical which promotes a chemical reaction
a chemical which reacts with sunlight
a cell with chlorophyll

Answers

a catalyst is a substance that increases the rate of a chemical reaction without itself being consumed . (ans: second choice)

[tex] \huge \mathrm{ \underline{Answer} ࿐}[/tex]

The correct option is B.

A Catalyst is a chemical which promotes or speed up a chemical reaction without undergoing any chemical reaction itself.

for example : potassium permanganate - Hydrogen peroxide will decompose into water and oxygen gas in the presence of KMnO4.

_____________________________

[tex]\mathrm{ \#TeeNForeveR}[/tex]

Calculate the concentration of NO2NO2 in an equilibrium mixture given that the concentration of N2O4=0.200MN2O4=0.200M and Keq=67.3Keq=67.3 for the reaction: 2NO2(g)⇌N2O4(g)2NO2(g)⇌N2O4(g). Calculate the concentration of in an equilibrium mixture given that the concentration of and for the reaction: . 18.3 M 0.00297 M 337 M 0.0545 M none of the above

Answers

Answer: The concentration of [tex]NO_{2}[/tex] in the given equilibrium mixture is 0.0545 M.

Explanation:

The ratio of concentration of products and reactants raised to the power of their coefficients is called equilibrium constant. The symbol used to denote equilibrium constant is [tex]K_{eq}[/tex].

As the given reaction equation is as follows.

[tex]2NO_{2}(g) \rightleftharpoons N_{2}O_{4}(g)[/tex]

The expression for equilibrium constant of this reaction is as follows.

[tex]K_{eq} = \frac{[N_{2}O_{4}]}{[NO_{2}]^{2}}[/tex]

Now, substitute the given values into above formula as follows.

[tex]K_{eq} = \frac{[N_{2}O_{4}]}{[NO_{2}]^{2}}\\67.3 = \frac{(0.2)}{[NO_{2}]^{2}}\\So, [NO] = \sqrt{\frac{0.2}{67.3}}\\= 0.0545 M[/tex]

Thus, we can conclude that the concentration of [tex]NO_{2}[/tex] in the given equilibrium mixture is 0.0545 M.

Which of the following lists contain ONLY metals?

Answers

Answer:

I'd there and pictures?? can put the list

How many moles are in 153 grams of O2?

Answers

Answer:

4.78 mol O2

Explanation:

Grams --> moles

Grams/molar mass = moles

153 g O2 / 32 g/mol O2 = 4.78125 (significant figures so round it up; the grams has 3 significant figures, so round it up) 4.78 mol O2

How do new traits enter a population?

Answers

Answer: By the way that population is treated and also by new borns.

Explanation: new borns are given traits based off their parents but also new traits that are developed off of their own. Now if that population has access to resources and a lot of it. Chances are they will become bratty,selfish and things such as.

What is my formula? Silver l acetate

Answers

Answer:

Ag(I)C2H3O2 ....................

Silver only has a single valence value (+1) so you really don't need to put the (I) in the chemical formula.

how does the study of genetics and Dna
help the study of evolution

Answers

Answer: DNA shapes how an organism grows up and the physiology of its blood, bone, and brains. DNA is thus especially important in the study of evolution . The amount of difference in DNA is a test of the difference between one species and another – and thus how closely or distantly related they are.

Select the correct answer.
Your friend Keith has been in a dating relationship for six months. His personality has changed in these months. He looks unhappy and rarely smiles. He avoids the company of friends. On the rare occasions you have seen him, his face appears bruised. You suspect that Keith may be in an abusive relationship. What should you do in this case?
A.
avoid talking to Keith
B.
confront his dating partner
C.
encourage Keith to speak up and report abuse
D.
advise him to tolerate the abuse, as difficulties are a part of life

Answers

I think c cause if he is in a relationship that’s abusive he needs to speak up before it goes way worst.
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