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
Colt1911 [192]
2 years ago
6

5.20763 to three significant figures​

Chemistry
1 answer:
Sergio039 [100]2 years ago
5 0

Answer:

5.21

Explanation: You can only have 3 digits, so you would round to the hundredths place

You might be interested in
If 1.02 g of nickel reacted with 750. mL of 0.112 M hydrobromic acid, how much of each will be present at the end of the reactio
kati45 [8]

Answer:

35.1% is percent yield

Explanation:

<em>Full question: Assume no volume change.  If you formed 0.0910 atm of gas, what is the percent yield?</em>

<em />

The reaction that is occurring is:

Ni + 3HBr → NiBr₃ + 3/2H₂(g)

First, we will determine moles of Ni and HBr to determine limiting reactant and theoretical yield

Using ideal gas law, we can determine the moles of hydrogen formed. Thus, we can find percent yield:

<em>Moles Ni (Molar mass: 58.69g/mol):</em>

1.02g * (1mol / 58.69g) = 0.01738moles Ni

<em>Moles HBr:</em>

0.750L * (0.112mol/L) = 0.084 moles of HBr.

For a complete reaction of the 0.084 moles of HBr you need:

0.084mol HBr * (1 mole Ni / 3 moles HBr) = 0.028 moles of Ni.

As there are just 0.01738 moles of Ni, the Ni is limiting reactant. Assuming a theoretical yield, moles of H₂ produced are:

0.01738moles Ni * (3/2 H₂ / 1 mol Ni) = 0.02607 moles H₂

Now, moles of H₂ produced are:

PV = nRT

PV/RT = n

<em>Where P is pressure (0.0910atm)</em>

<em>V is volume (2.50L)</em>

<em>R is gas constant (0.082atmL/molK)</em>

<em>T is absolute temperature in Kelvin (30°C + 273.15 = 303.15K)</em>

<em>And n are moles</em>

PV/RT = n

0.0910atm*2.50L/0.082atmL/molK*303.15K = n

0.00915 moles = n

<em />

And percent yield (Produced moles / Theoretical moles * 100) is:

0.00915 moles / 0.02607moles =

<h3>35.1% is percent yield</h3>
8 0
2 years ago
An atom emits a photon of wavelength 1.08 meters. What is the energy change occurring in the atom due to this emission? (Planck'
kati45 [8]
The answer is 1.84×10^(-25).
4 0
2 years ago
Read 2 more answers
What is the mass, in grams, of 28.58 mL of acetone?
Vedmedyk [2.9K]
<span>If you look up the density of Acetone (Propanone in IUPAC names) you will find it is 0.7925g/cm3. This is the same as 0.7925g/ml. 

You can calculate mass using the equation:- mass = density x volume 
In your example mass = 0.7925 x 28.40 = 22.51g</span><span>
I think That's right. Hope this helps!!! Good luck!</span>
7 0
3 years ago
Read 2 more answers
PLEASE HELP ME<br><br> what would be the mass of 9.03 x 1021 molecules of hydrobromic acid (HBr)?
Nikitich [7]

We know 1 mole of any atom or molecules contains 6.033 \times 10^{23} atom or molecules.

1 mole of HBr i.e 81 gm/mol contains  6.033 \times 10^{23} atom or molecules.

So, mass of 9.03\times 10^{21} molecules is :

m=\dfrac{81\times 9.03\times 10^{21} }{6.033 \times 10^{23}}\\\\m= 1.21\ gm

Therefore, mass of  9.03\times 10^{21} molecules is 1.21 gm .

Hence, this is the required solution.

7 0
3 years ago
A radioactive element reduces to 5.00% of its initial mass in
Stolb23 [73]

The half-life in months of a radioactive element that reduce to 5.00% of its initial mass in 500.0 years is approximately 1389 months

To solve this question, we'll begin by calculating the number of half-lives that has elapsed. This can be obtained as follow:

Amount remaining (N) = 5%

Original amount (N₀) = 100%

<h3>Number of half-lives (n) =?</h3>

N₀ × 2ⁿ = N  

5 × 2ⁿ = 100

2ⁿ = 100/5

2ⁿ = 20

Take the log of both side

Log 2ⁿ = log 20

nlog 2 = log 20

Divide both side by log 2

n = log 20 / log 2

<h3>n = 4.32</h3>

Thus, 4.32 half-lives gas elapsed.

Finally, we shall determine the half-life of the element. This can be obtained as follow.

Number of half-lives (n) = 4.32

Time (t) = 500 years

<h3>Half-life (t½) =? </h3>

t½ = t / n

t½ = 500 / 4.32

t½ = 115.74 years

Multiply by 12 to express in months

t½ = 115.74 × 12

<h3>t½ ≈ 1389 months </h3>

Therefore, the half-life of the radioactive element in months is approximately 1389 months

Learn more: brainly.com/question/24868345

8 0
2 years ago
Other questions:
  • From laboratory measurements, we know that a particular spectral line formed by hydrogen appears at a wavelength of 486.1 nanome
    12·1 answer
  • What are points a and b? What does this diagram show? Whats point c?
    10·1 answer
  • A solution is made by dissolving 23.0 g KOH in 1.60 L H2O. What is the molality of the solution? The density of water is 1.00 g/
    9·2 answers
  • You have 125.0 mL of a solution of H3PO4, bu you don't know its concentration. if you titrate the solution with a 4.56-M solutio
    5·1 answer
  • Susan and her friend found a piece of metal which they want to
    7·1 answer
  • The potential difference across the terminals of a battery of e.m.f. 12 V and internal resistance 2 ohm drops to 10 V when it is
    6·1 answer
  • What is used to measure the energy in a chemical reaction?
    8·2 answers
  • Balance Cl2+NaBr=NaCl+Br2​
    11·1 answer
  • Consider the synthesis of water as shown in Model 3. A container is filled with 10.0 g of H2 and 5.0 g of O2.
    6·1 answer
  • How many hydrogen bonds will be found within an alpha helix that is 18 amino acids long?.
    7·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!