Answer: Refraction
Explanation: i took the test
2H2 (1) + O2(g) → 2H20 (g)
1. Find the limiting reactant if you start with 30.0 grams of hydrogen and 5.29 grams of oxygen.
2. The actual yield for H2O in the above reaction is 6.72 g, Determine the percent yield for the reaction
when 9.93 grams of hydrogen and excess oxygen react?
Answer: 1. Oxygen is the the limiting reactant.
2. 7.52%
Explanation:
The balanced chemical equation is:
[tex]2H_2(g)+O_2(g)\rightarrow 2H_2O(g)[/tex]
To calculate the moles :
[tex]\text{Moles of solute}=\frac{\text{given mass}}{\text{Molar Mass}}[/tex]
[tex]\text{Moles of} H_2=\frac{30.0g}{2g/mol}=15.0moles[/tex]
[tex]\text{Moles of} O_2=\frac{5.29g}{32g/mol}=0.165moles[/tex]
According to stoichiometry :
1 mole of [tex]O_2[/tex] require = 2 moles of [tex]H_2[/tex]
Thus 0.165 moles of [tex]O_2[/tex] will require=[tex]\frac{2}{1}\times 0.165=0.331moles[/tex] of [tex]NH_3[/tex]
Thus [tex]O_2[/tex] is the limiting reagent as it limits the formation of product and [tex]H_2[/tex] is the excess reagent.
2. [tex]\text{Moles of} H_2=\frac{9.93g}{2g/mol}=4.96moles[/tex]
[tex]\text{Moles of} H_2O=\frac{6.72g}{18g/mol}=0.373moles[/tex]
As 2 moles of [tex]H_2[/tex] give = 2 moles of [tex]H_2O[/tex]
Thus 4.96 moles of [tex]H_2[/tex] give =[tex]\frac{2}{2}\times 4.96=4.96moles[/tex] of [tex]H_2O[/tex]
percentage yield = [tex]\frac{\text {actual yield}}{\text {theoretical yield}}=\frac{0.373}{4.96}\times 100=7.52\%[/tex]
Thus the percent yield for the reaction is 7.52%
A chemist dissolves of pure potassium hydroxide in enough water to make up of solution. Calculate the pH of the solution. (The temperature of the solution is .) Be sure your answer has the correct number of significant digits.
Answer:
12.99
Explanation:
A chemist dissolves 716. mg of pure potassium hydroxide in enough water to make up 130. mL of solution. Calculate the pH of the solution. (The temperature of the solution is 25 °C.) Be sure your answer has the correct number of significant digits.
Step 1: Given data
Mass of KOH: 716. mg (0.716 g)Volume of the solution: 130. mL (0.130 L)Step 2: Calculate the moles corresponding to 0.716 g of KOH
The molar mass of KOH is 56.11 g/mol.
0.716 g × 1 mol/56.11 g = 0.0128 mol
Step 3: Calculate the molar concentration of KOH
[KOH] = 0.0128 mol/0.130 L = 0.0985 M
Step 4: Write the ionization reaction of KOH
KOH(aq) ⇒ K⁺(aq) + OH⁻(aq)
The molar ratio of KOH to OH⁻is 1:1. Then, [OH⁻] = 0.0985 M
Step 5: Calculate the pOH
We will use the following expression.
pOH = -log [OH⁻] = -log 0.0985 = 1.01
Step 6: Calculate the pH
We will use the following expression.
pH + pOH = 14
pH = 14 - pOH = 14 -1.01 = 12.99
Help me please) attached the screen below. Thanks
Answer:
1) d = 2.4 g/cm³
2) m = 25 g
3) v = 126.7 cm³
Explanation:
Given data:
Mass of material = 24 g
Volume of material = 10 cm³
Density of material = ?
Solution:
Formula:
d = m/v
by putting value,
d = 24 g / 10 cm³
d = 2.4 g/cm³
2) Given data:
Density of material = 5 g/cm³
Volume of material = 5 cm³
Mass of material = ?
Solution:
Formula:
d = m/v
5 g/cm³ = m / 5 cm³
m = 5 g/cm³×5 cm³
m = 25 g
3)Given data:
Density of material = 3 g/cm³
Mass of material = 380 g
Volume of material = ?
Solution:
Formula:
d = m/v
3 g/cm³ = 380 g / v
v = 380 g /3 g/cm³
v = 126.7 cm³
what is the answer I needed now please quickly
Severe or sudden changes in Earth's atmosphere can cause entire species of animals to die. When all of the members of species die out, it is called
Answer: Extinction
Animals on the verge of extinction are considered endangered species. Some could argue that the phrasing "threatened" is synonymous to "endangered". Some classify extinction based on if the species is completely wiped out in the wild, or if the species is completely gone (both in the wild and in zoos for instance). Extinction events are not solely due to the changes in atmosphere, but also due to lack of food or habitat, among other possible factors.
Because of the magnetic field, magnets do have to touch to affect each other. Question 6 options: True False
Answer:
False, they can interact without touching
how many electrons does cesium gain or lose
22. Which statement best describes the use of catalytic converters in automobiles?
(1 point)
They decrease the rate of the reactions that produce harmful gases.
They oxidize hydrocarbons to form less toxic gases.
They combine the larger hydrocarbon molecules with smaller ones.
They increase reaction temperature for cleaner burning.
Answer:
B. They oxidize hydrocarbons to form less toxic gases.
Explanation:
A catalytic converter can be defined as an anti-pollution device containing a catalyst like platinum-iridium, installed in the exhaust chamber of an automobile so as to chemically convert harmful (poisonous) pollutants such as unburned hydrocarbons and carbon monoxide (CO), sulfur dioxide (S02), nitrogen oxide (NO) etc., into less harmful, poisonous or toxic chemical compounds.
This ultimately implies that, catalytic converters are typically used for converting harmful gases into less harmful, poisonous or toxic gases and molecules e.g carbon dioxide (C02) and water (H2O). This helps to prevent global warming, enhance the conservation of natural resources, as well as preserve the lives of living organisms and their natural habitat.
Hence, the statement which best describes the use of catalytic converters in automobiles is that they oxidize hydrocarbons to form less toxic gases.
Smallest particle of a substance that can retain its properties & is
composed of one or more atoms *
O A. Atom
O B. Molecules
O C. Matter
O D. Everything
Answer:
Molecules
Explanation:
What is the density of lead (in g/cm^3 3 ) if a rectangular bar measuring 0.500 cm in height, 1.55 cm in width, and 25.00 cm in length has a mass of 220.9 g? Report the answer with the units of g/cm^3 3 and the proper number of significant figures. Numbers in bold count towards significant figures. Type your answer here with correct significant figures and units:
Answer:
Density = 11.4 g/cm³
Explanation:
Given data:
Density of lead = ?
Height of lead bar = 0.500 cm
Width of lead bar = 1.55 cm
Length of lead bar = 25.00 cm
Mass of lead bar = 220.9 g
Solution:
Density = mass/ volume
Volume of bar = length × width × height
Volume of bar = 25.00 cm × 1.55 cm × 0.500 cm
Volume of bar = 19.4 cm³
Density of bar:
Density = 220.9 g/ 19.4 cm³
Density = 11.4 g/cm³
A mole of Cu (Copper) is equal to...
Answer:
hi
Explanation:
i think 63.55 g
hope it helps have a nice day
good bye: )
Answer:
Explanation:
A mole of Cu (Copper) is equal to 63.55g
Which type of bond has an equal sharing of electrons?
covalent bonds
The equal sharing of electrons in a covalent bond is called a nonpolar covalent bond.
Which of these elements has the smallest atomic radius?
A. Se
B. Br
C. Ge
D. As
Answer:
Its Br on Ap ex
Explanation:
Just got it wrong ;( it's B
The vapor pressure of ethanol, CH3 CH2 OH, at 40.0 °C is 17.88 kPa. If 2.24 g of ethanol is enclosed in a 3.00 L container, how much liquid will be present?
Answer:
7.13 L of ethanol, CH₃CH₂OH
Explanation:
We'll begin by calculating the number of mole in 2.24 g of ethanol. This can be obtained as follow:
Mass of CH₃CH₂OH = 2.24 g
Molar mass of CH₃CH₂OH = 12 + (3×1) + 12 + (2×1) + 16 + 1
= 12 + 3 + 12 + 2 + 16 + 1
= 46 g/mol
Mole of CH₃CH₂OH =?
Mole = mass / molar mass
Mole of CH₃CH₂OH = 2.24 / 46
Mole of CH₃CH₂OH = 0.049 mole
Next, we shall convert 40 °C to Kelvin temperature. This can be obtained as follow:
T(K) = T(°C) + 273
T(°C) = 40 °C
T(K) = 40 °C + 273
T(K) = 313 K
Finally, we shall determine the volume of ethanol, CH₃CH₂OH in present in the container. This can be obtained as follow:
Pressure (P) = 17.88 KPa
Temperature (T) = 313 K
Number of mole (n) = 0.049 mole
Gas constant (R) = 8.314 L.KPa/Kmol
Volume (V) =?
PV = nRT
17.88 × V = 0.049 × 8.314 × 313
Divide both side by 17.88
V = (0.049 × 8.314 × 313) / 17.88
V = 7.13 L
Thus, 7.13 L of ethanol, CH₃CH₂OH will be present in the container.
Based on the mass of ethanol provided, the mass of liquid ethanol is 1.61 g
What is the relationship between gas volume, pressure, temperature and moles?The relationship between the gas volume, pressure, temperature and moles is given by the ideal gas equation:
PV = nRTwhere:
P is pressureV is volumen is number of molesR is molar gas constant = 8.314 L.KPa/KmolT is temperatureFrom data provided:
P = 17.88 kPa
V = 3.00 L
T = 40.0 °C = 313 K
R = 0.049 mole
n = ?
n = PV/RT
n = 17.88 * 2/8.314 * 313
n = 0.0137 moles
Mass of ethanol gas = number of moles * molar mass
Mass of gaseous ethanol = 0.0137 mole * 46 g/mol
Mass of gaseous ethanol = 0.63 g
Then:
Mass of liquid ethanol, CH₃CH₂OH = 2.24 - 0.63
Mass of liquid ethanol, CH₃CH₂OH = 1.61 g
Therefore, the mass of liquid ethanol is 1.61 g
Learn more about vapor pressure and mass at:
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A 52.6 kg car is driving at a constant velocity of 20 m/s over 2 seconds. What is its acceleration?
Answer:
Centripetal acceleration is related to tangential velocity through ac = v ^ 2 / R
The angular velocity is related to the tangential velocity through ω = v / R
a) ac = (20 m / s) ^ 2/20 m = 20 m / s ^ 2
b) ω = 20 m / s / 20m = 1 rad / s
c) The swept angle is Ф = ω.t = 1 rad / s. 3600 s = 3600 rad
Expressed in turns it is Ф = 3600 rad. 1 turn / (2.π rad) = 573 turn
Explanation:
how many moles are there in 3.80x10^22 molecules of CCI4?
image attached and will give brainliest
Answer:
0.0646 mole.
Explanation:
The following data were obtained from the question:
Number of molecules = 3.89×10²² molecules
Number of mole =?
The number of mole present in 3.89×10²² molecules of CCl₄ can be obtained as follow:
From Avogadro's hypothesis:
6.02×10²³ molecules = 1 mole
Therefore,
3.89×10²² molecules = 3.89×10²² molecules × 1 mole / 6.02×10²³ molecules
3.89×10²² molecules = 0.0646 mole
Thus, 0.0646 mole is present in 3.89×10²² molecules of CCl₄.
1
What is an example of a phenotype?
A having dark hair
B. having dominant genes
C. having recessive genes
D. SS
Select the atoms that belong to the same element.
Answer:
the middle and bottom left
Explanation:
one is a positively charged atom, and the other is normal. they are both the same
Answer:
the middle and bottom left .
In what element will metallic bonding occur?
A.
Carbon
B.
Oxygen
C.
Argon
D.
Cobalt
Calculate the work associated with the expansion of a gas from 46 L to 64 L at a con-
stant extemal pressure of 15 atm.
Answer:
QhhjjgDjKfxockzgnx
Explanation:
DjiDfj,jzo
WILL MARK ASBRANLYST!!!!
All successful organisms must be able to do what three things? Question 1 options: A. obtain energy, eat, play video games B. obtain energy, produce offspring, maintain their structure C. maintain their structure, eat, build a home D. obtain energy, produce offspring, eat
Answer:obtain and use resources, grow, reproduce, and maintain stable internal conditions while living in a constantly changing external environment.
Explanation:
All successful organisms must be able to do the three things including obtain energy, produce offspring, maintain their structure. The correct option is B.
What is an organism?In biology, an organism is any natural, living system that functions as a separate entity. Cells make up all organisms.
Taxonomy divides organisms into groups such as multicellular animals, plants, and fungi, or unicellular microorganisms such as protists, bacteria, and archaea.
The current classification system is based on the Linnean system and has eight levels of taxa: domain, kingdom, phylum, class, order, family, genus, and species.
All successful organisms must be able to do three things: obtain energy, generate progeny, and maintain their respective structure.
Thus, the correct option is B.
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which formula represents a molecule solid
Dry ice are the molecule which represent molecular solid. Hence option c is correct.
What are molecule?Molecules are defined as the lowest identifiable unit into which a pure material can be divided while maintaining its chemical makeup and attributes is made up of two or more atoms. When two or more atoms come together and form bonds with one another, a molecule is created. Each atom shares an electron when a bond is formed between them. A molecule is created as a result of a covalent bond.
Molecular solid are defined as composed of atoms or molecules joined by hydrogen bonds, London dispersion forces, and dipole-dipole forces. Solids made of molecules and held together by van der Waals forces are referred to as molecular solids. Examples include carbon dioxide, hydrogen, etc. Crystalline solids include ZnS. The ionic solid MgO is. Diamond is organized in a network.
Thus, dry ice are the molecule which represent molecular solid. Hence option c is correct.
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Your question is incomplete, but probably your complete question was
Which of the following is an example of molecular solid?
a. Zinc sulphide
b. Magnesium oxide
c. Dry ice
d. Diamond
Write down the formulas of the following compounds: magnesium chloride, alumina, chlorine (VII) oxide, sodium sulfide, calcium oxide.
Answer:
- Magnesium chloride: MgCl₂.
- Alumina: Al₂O₃.
- Chlorine (VII) oxide: Cl₂O₇.
- Sodium sulfide: Na₂S.
- Calcium oxide: CaO.
Explanation:
Hello!
In this case, according to the naming rules for the given compounds, which state that binary salts have a metal and a nonmetal and oxides contain oxygen, we have:
- Magnesium chloride: MgCl₂.
- Alumina: Al₂O₃.
- Chlorine (VII) oxide: Cl₂O₇.
- Sodium sulfide: Na₂S.
- Calcium oxide: CaO.
Best regards!
How does ocean temperatures very around the globe?
PLZ HELP ME
Answer:
As the oceans absorb more heat, sea surface temperature increases and the ocean circulation patterns that transport warm and cold water around the globe change
Explanation:
The radius of a gold atom is 144 pm. How many gold atoms would have to be laid side by side to span a distance of 4.97 mm
Answer:
2.18 × 10⁷ Au atoms
Explanation:
Step 1: Calculate the diameter of a gold atom
The diameter is twice the radius.
d = 2 × r = 2 × 144 pm = 228 pm
Step 2: Convert "d" to meters
We will use the conversion factor 1 m = 10¹² pm.
228 pm × 1 m/10¹² pm = 2.28 × 10⁻¹⁰ m
Step 3: Convert the total distance to be covered (D) to meters
We will use the conversion factor 1 m = 10³ mm.
4.97 mm × 1 m/10³ mm = 4.97 mm × 10⁻³ m
Step 4: Calculate the number of atoms of gold required
We will divide the total distance by the diameter of 1 atom of gold.
D/d = 4.97 mm × 10⁻³ m/2.28 × 10⁻¹⁰ m = 2.18 × 10⁷
What does the interquartile range represent?
A
the lower 50 percent of the data
B
the higher 50 percent of the data
C
the middle 50 percent of the data
D
the middle data point
Answer: C) middle 50 percent of the data
The interquartile range (IQR) spans from the first quartile Q1 to the third quartile Q3.
25% of the data is below Q1 and 75% of the data is below Q3. The gap between the two endpoints consists of 75-25 = 50 percent of the data, or half of the data.
The middle 50 percent of the data. Therefore, option (C) is correct.
The interquartile range (IQR) shows the spread or dispersion of a dataset. It is calculated as the difference between the third quartile (Q3) and the first quartile (Q1) in a sorted dataset. The first quartile (Q1) is the value below which 25 percent of the data falls, and the third quartile (Q3) is the value below which 75 percent of the data falls.
The interquartile range captures the range of the central 50 percent of the data. It provides a measure of the variability or spread of the middle portion of the dataset while excluding the influence of extreme values or outliers.
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If data comes in that disproves a theory, what will happen to the theory?
Answer: More conservative scientists will try to modify the existing theory to fit the new data. The last answer, the fourth one.
Explanation: I think I had this question before, hope it helps!
PLEASE HELP it would be really nice of you to answer this question i would be very grateful <3
If an element has three isotopes with known masses, what other information
is needed to find the average atomic mass of the element?
A. The number of neutrons in each isotope
B. The average mass of the isotopes
C. The atomic number of each isotope
D. The abundance percentage of each isotope
Answer: D (The abundance percentage of each isotope)
Explanation: hope this helps!
I need help on this question
Answer:
warm blooded
Explanation:
humans are warm blooded. we cannot change our body temperature as we want to
if i have 4 moles of a gas at a pressure of 5 atm and a volume of 12 liters what is the temperature?
Answer:
182.70K
Explanation:
Using the general gas equation as follows:
PV = nRT
Where;
P = pressure (atm)
V = volume (L)
n = number of moles (mol)
R = 0.0821 Latm/Kmol
T = temperature (K)
Based on the provided information, P = 5 atm, V = 12L, n = 4 moles, T =?
PV = nRT
5 × 12 = 4 × 0.0821 × T
60 = 0.3284T
T = 60/0.3284
T = 182.70K
