Answer:
Average atomic mass of E = 103.57 amu
Explanation:
Given data:
Average atomic mass of E = ?
Abundance of E-102.658 = 56.67%
Abundance of E-104.770 = 43.33%
Solution:
Average atomic mass of E = (abundance of 1st isotope × its atomic mass) +(abundance of 2nd isotope × its atomic mass) / 100
Average atomic mass of E = (56.67×102.658)+(43.33×104.770) /100
Average atomic mass of E = 5817.63 + 4539.68 / 100
Average atomic mass of E = 10357.31 / 100
Average atomic mass of E = 103.57 amu.
A compound has a molar mass of 100 g/mol and the percent composition (by mass) of 65.45% C, 5.45% H, and 29.09% 0. Determine the empirical formula and the molecular formula.
A) CHO and C6H6O6
B) C3H3O and C6H6O2
C) C3HO and C6H2O2
D) CH2O and C4H8O4
E) CH4O and C3H12O3
Answer:
B) C3H3O and C6H6O2
Explanation:
Given data:
Molar mass of compound = 100 g/mol
Percentage of hydrogen = 5.45%
Percentage of carbon = 65.45%
Percentage of oxygen = 29.09%
Empirical formula = ?
Molecular formula = ?
Solution:
Number of gram atoms of H = 5.45 / 1.01 = 5.4
Number of gram atoms of O = 29.09/ 16 = 1.8
Number of gram atoms of C = 65.45 / 12 = 5.5
Atomic ratio:
C : H : O
5.5/1.8 : 5.4/1.8 : 1.8/1.8
3 : 3 : 1
C : H : O = 3 : 3 : 1
Empirical formula is C₃H₃O.
Molecular formula:
Molecular formula = n (empirical formula)
n = molar mass of compound / empirical formula mass
Empirical formula mass = 12×3 + 1.01 ×3 + 16×1 = 55.03
n = 100 / 5503
n = 2
Molecular formula = n (empirical formula)
Molecular formula = 2 (C₃H₃O)
Molecular formula = C₆H₆O₂
How did modern scientists experiment with Van Gogh's paints to determine their chemical reactions?
1. They used X-ray analysis.
2. They used litmus testing.
3. They burned the paint to examine what elements were left after the chromium was burned off.
4. They studied the density of modern yellow paint to that of 100-year-old paint.
Answer:
I think the answer is A - they used X-ray analysis.
Explanation:
Answer:They used X-ray analysis
Explanation:
It’s in the text
Which are not combination reactions?
Check all that apply.
A. 2H2O + 2H2 + O2
B. H2 + Cl2 → 2HCI
C. Fe + MgO + Mg + FeO
D. 2Na + Cl2 → 2NaCl
Answer:
A and c
Explanation:
In A the product is added to the reactant, so the real reaction is (2H2O = 2H2+O2).
In B hydrogen and clorine are combined to give hydrochloric acid and 2 is used to balance the reaction in the product, so it's a combination reaction .
In C the case is similar to A , so the real reaction is (Fe+MgO = Mg + FeO ) this is displacement reaction where a more reactive element takes place of a less reactive element .
In D sodium reacting with Chlorine to give sodium chloride ,so we conclude that it's a combination reaction .
please help me with this question/
Answer:
4 of each protons and electrons
Explanation:
since the atomic number is 4 it would contain both the same number of protons and electrons
Write the complementary RNA strand for the following DNA strand. TAC ACC TTG ACG
Answer:
ATG TGG AAC TGC
Explanation:
ATG TGG AAC TGC
Convert a measurement of 89 cg to its equivalent in mg
Answer:
1 cg = 10 mg
Explanation:
So, 89cg = 89 * 10 = 890mg!
Pls thank, 5star, and brainliest!
What is the Sl unit for energy? Be sure to give the full name for the unit
Answer:
Joules
Explanation:
is mass conserved in 2Na+2H2O=2NaOH+H2
Answer:
yes mass conservation is in 2Na+2H2O=2NaOH+H2
Explanation:
it tells how many atoms or molecules of a reactant or a product take part in the reaction
True or False- Waves are caused by the water being pushed by the wind, which transfers energy, that can cause erosion to the shorelines .
Answer:
false
Explanation:
Waves are created because othe the lunar pull with out the moon we wouldnt have waves
A 170.0 g sample of an unidentified compound contains 29.84 g sodium, 67.49
g chromium, and 72.67 g oxygen. What is the compound's empirical formula?
The empirical formula : Na₂Cr₂O₇
Further explanationGiven
170 g sample contains :
29.84 g sodium, 67.49 g chromium, and 72.67 g oxygen
Required
The compound's empirical formula
Solution
mol ratio of elements :
Na : 29.84 : 23 g/mol = 1.297
Cr : 67.49 : 51,9961 g/mol = 1.297
O : 72.67 : 16 g/mol = 4.54
Divide by 1.297
Na : Cr : O = 1 : 1 : 3.5 = 2 : 2 : 7
What is the atomic mass of this atom?
Answer:
3
Explanation:
The atomic mass is equal to the number of protons in an atom (and electrons if the atom is neutral).
whoever answers first will get brainliest! this is times so pls help!
You are titrating a 125 mL sample of KOH solution; the pH meter reads 7.00 after the addition of 84.7 mL of 0.750 M HNO3.
What is the concentration of the KOH solution?
A. 0.125 M KOH
B.0.750 M KOH
C.0.508 M KOH
D. 0.0635 M KOH
thanks so much!
If she traveled 10 m in 5 seconds, what was her average speed?
Please answer this question please brianlest
How many moles are in 6.777 x 1023 atoms of CO2. Watch your significant figures. Question 2 options: 1 atoms CO2 1.125 moles CO2 1.13 moles 1.13 atoms CO2
Answer:
1.13moles
Explanation:
Given parameters:
Number of atoms = 6.777 x 10²³ atoms
Unknown:
Number of moles = ?
Solution:
A mole of a substance contains the avogadro's number of particles
6.02 x 10²³ particles = 1 mole
6.777 x 10²³ atoms will contain [tex]\frac{ 6.777 x 10^{23} }{6.02 x 10^{23} }[/tex] = 1.13moles
Why did early people most likely choose to settle in Mesopotamia?
Answer:
People wanted to settle there because it had good living conditions. There was rich soil, and lots of water sources.
I hope this helps!
The answers plzzzzzzz
Answer:
ok, whats the question
Explanation:
Tectonic Plates
Tectonic Plates
Which of the following is an accurate description of the movement of the tectonic plates in the diagram?
O A. Plate A is sliding past plate B.
O B. Plate A and plate B are diverging.
OC. Plate A and plate B are of equal density and are colliding.
OD. Plate A is denser than plate B, which results in subduction.
By February of 1861, how many states seceded from the Union?
5
11
9
7
Answer:
D. 7
Explanation:
i did it
4. How many moles of H, would be
produced from 47 grams of H2SO4?
2A1 +3H,504 → Al2(SO4)3 +3H2
Answer:
0.48 moles of H₂ are produced.
Explanation:
Given data:
Number of moles of H₂ produced = ?
Mass of H₂SO₄ = 47 g
Solution:
Chemical equation:
2Al + 3H₂SO₄ → Al₂(SO₄)₃ + 3H₂
Number of moles of H₂SO₄ :
Number of moles = mass/molar mass
Number of moles = 47 g/ 98 g/mol
Number of moles = 0.48 mol
Now we will compare the moles of H₂SO₄ and H₂
H₂SO₄ : H₂
3 : 3
0.48 : 0.48
Thus, 0.48 moles of H₂ are produced.
An apple, potato, and onion all taste the same if you eat them with your nose plugged
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Hey, love!
You only get that little quote if your streak gets higher so, congrats on that!
Keep it up, stay lovely!
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Which of the following requires more energy then they produce?
Exothermic
Endothermic
(the subject is science but it wasn’t an option)
Answer:
The answer is endothermic
Something that is made out of natural resources for human use is called
Answer:
Man-made resources
Explanation:
Humanized resources are items or substances that have value to human lives that do not occur in the natural world. Examples of man-made resources include plastic, paper, soda, sheet metal, rubber and brass. These contrast with natural resources, such as water, crops, sunlight, crude oil, wood and gold.
what does 'potable water' mean?
Answer:
Potable water, also known as drinking water, comes from surface and ground sources and is treated to levels that that meet state and federal standards for consumption.
Precipitation falls in these two forms: Solid / Liquid / Gas I’ll give you 77 and read the pdf
Answer:
It falls in Liquid and Solid.
Explanation:
The sum of the atomic masses for any compound is the compound’s:
Empirical mass
Compound mass
Atomic mass
Molar mass
Balance the chemical equation. Based on the equation, how many grams of bromine are produced by the complete reaction of 11 grams of potassium bromide?
Answer:
Explanation:
The balanced chemical equation is Cl2 + 2KBr → 2KCl + Br2. The amount of bromine is calculated as follows:
11.0 g KBr (1mol KBr/119.002g KBr * 1mol Br2/2mol KBr * 159.808g Br2/1mol Br2= 7.39 g Br2.)
True/False: Atoms of the same elements have different properties
Answer: True
Explanation:
If the temperature of a gas in a balloon remains constant but the pressure
is decreased, the volume of the balloon will
decrease
increase
remain the same
not enough information to predict
Answer:
increase
Explanation:
if the pressure goes down then the gas will spread out more, meaning the volume will increase
Scott and his classmates were looking at an animal cell under a microscope. They are trying to locate the cell's DNA, which is found in its chromosomes. Where should Scott look to find the chromosomes?
In the mitochondria
In the cell nucleus
In the cytoplasm
In the cell vacuole