Answer:
true
Explanation:
PV=nRT
The ideal gas law states that PV = NkT, where P is the absolute pressure of a gas, V is the volume it occupies, N is the number of atoms and molecules in the gas, and T is its absolute temperature. The constant R is called the Boltzmann constant
Analysis of an ore of calcium shows that it contains 13.61 g calcium and 21.77 g oxygen in a 46.28-g sample. Calculate the percent composition of this compound.
Answer:
29.41% of Calcium and 47.04% of Oxygen
Explanation:
The percent composition of an atom in a molecule is defined as 100 times the ratio between the mass of the atom and the mass of the molecule.
The mass of the molecule of the problem (Ore) is 46.28g. That means the percent composition of Calcium is:
13.61g / 46.28g * 100 = 29.41% of Calcium
And percent composition of Oxygen is:
21.77g / 46.28g * 100 = 47.04% of Oxygen
BJECTIVE TYPE QUESTIONS
Fill in the blank spaces by choosing the correct words from the words given in list.
List : composition, heat, chemical, photosynthesis, physical
1. Heating of zinc oxide is a
change.
2. Burning of coal is a
change.
3. There is a change in state and
during a chemical change.
4. Plants make their food by the process of
5.
energy is generally given out or absorbed during a chemical change
Answer:
1.Physical change
2. Chemical change
3. Heat
4.photosynthesis
5. composition
PLZZZ HELP ME ASAP
Use the de Broglie's Wave Equation to find the wavelength of a 400 g ball moving at 120 m/s. Please show your work. Note: h = Planck's constant (6.62607 × 10-34 J*s)
de Broglie's wave equation describes that particles have wave properties. The equation is
λ = h/mv
Where λ is the wave length of the particle (m), h is the Planck's constant (6.62607 x 10⁻³⁴J s), m is the mass of a particle (kg) and v is the velocity (m/s).
λ = ?
h = 6.62607 x 10⁻³⁴ J s
m =200 g = 0.2 kg
v = 20 m/s
By substitution,
λ = 6.62607 x 10⁻³⁴ J s / (0.2 kg x 20 m/s)
λ = 1.66 x 10⁻³⁴ m
Hence, the wavelength of the 200 g ball 1.66 x 10⁻³⁴ m.
find out the maximum number of electrons that can be accommodate in m sell using 2n² rule
[tex]okay \: bro[/tex]
Answer is [tex]32[/tex]
Explanation:
There are mainly four shells in an atom namely K, L, M, and N.
By using 2n², we can find the maximum number of electrons present in M shell.
Let, K = 1st shell, L = 2nd shell, M = 3rd shell, and N = 4th shell.
K = 1, L = 2, M = 3 and N = 4.
K = 2n² = 2(1)² = 2(1) = 2.
L = 2n² = 2(2)² = 2(4) = 8.
M = 2n² = 2(3)² = 2(9) = 18.
N = 2n² = 2(4)² = 2(16) = 32.
So, The maximum number of electrons present in the M shell is [tex]32.[/tex]
Values for the molar mass of hydrogen, oxygen, and water molecules are
given in the table below. What mass of water is formed when 2 moles of
hydrogen react with 1 mole of oxygen to form water?
Molecule
Molar mass (g/mol)
H2
2.02
02
32.00
H20
18.01
A.9.00 g
B. 36.02 g
C. 2.00 g
D. 18.01 g
Answer:
36.02g bbbbbbbbbbb hbbnjkkkj
Answer:
36.02g
Explanation:
Hope this helps!
Match each lab incident to the item of PPE that will protect you from it. Each item of PPE will only be used once.
While picking up a buret, an unknown solution left by a previous solution drips onto your hand._______________
While pulling an empty beaker off the shelf at the beginning of lab, it slips out of your hand onto the floor _______
While checking on a stirring solution, the solution splashes up towards your face. _______
While transferring a solution from a flask to a beaker, the solution accidentally spills down the front of the lab bench, __________
A. Gloves
B. Lab coat
C. Goggles
D. Closed-toe shoes
While picking up a buret, an unknown solution left by a previous solution drips onto your hand - Gloves
While pulling an empty beaker off the shelf at the beginning of lab, it slips out of your hand onto the floor - Closed-toe shoes
While checking on a stirring solution, the solution splashes up towards your face - Goggles
While transferring a solution from a flask to a beaker, the solution accidentally spills down the front of the lab bench - Lab coat
Explanation:
The full form of PPE is 'Personal Protective Equipment'.The PPE items we use in labs are : Lab coat: Protection of clothing and skin from accidental spilling of hot liquid or toxic substances. Gloves: Protection from hands from chemicals, hot objects, sharp tools, or electricityGoggles: Protection of the eye from any chemicals, toxic vapor, chemical debrisFace shield: Protection of the face from any chemicals, toxic vapor, chemical debrisClosed-toe shoes: Protection from feet from chemicals, hot objects, sharp tools, or electricitySo, according to the question. the matches will be:
While picking up a buret, an unknown solution left by a previous solution drips onto your hand - Gloves
While pulling an empty beaker off the shelf at the beginning of lab, it slips out of your hand onto the floor - Closed-toe shoes
While checking on a stirring solution, the solution splashes up towards your face - Goggles
While transferring a solution from a flask to a beaker, the solution accidentally spills down the front of the lab bench - Lab coat
Learn more about PPE here:
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2. Nitric oxide contains 46.66% nitrogen and 53.34% oxygen. Water contains 11.21% hydrogen and 88.79% oxygen. Ammonia contains 17.78% hydroger and 82.22% nitrogen. Use these data to verify the law of reciprocal proportions.
Answer:
The law of reciprocal proportions states that if two elements react individually with a given weight of a third element, the ratio of the masses with which they combine with the third element are either the same or a simple multiple of the ratio of the masses with which they combine with each other
The compounds formed includes;
1) Nitric oxide, NO
Nitrogen = 46.66% × 30.01 = 14
Oxygen = 53.34% × 30.01 = 16
2) Water, H₂O
Hydrogen = 11.21% × 18.01528 = 2
Oxygen = 88.79% × 18.01528 ≈ 16
3) Ammonia, NH₃
Hydrogen = 17.78% × 17.031 ≈ 3
Nitrogen = 82.22% × 17.031 ≈ 14
The ratio of nitrogen to oxygen in nitric oxide = 14:16 = 7:8
The ratio of nitrogen to hydrogen in ammonia = 14:3
The ratio in which hydrogen and oxygen combine with nitrogen = 3/16
The ratio of hydrogen and oxygen combine with each other in water = 2/16
Therefore, the ratio with which hydrogen and oxygen combine with nitrogen, is (2/3) times the ratio with which they combine with each other, which verifies the law of reciprocal proportions
Explanation:
Scientists in a lab are working on a series of experiments that involve colliding two or more atomic nuclei at very high speeds to form a new type of atomic nucleus. What are they working on?
convection
radiation
nuclear fusion
nuclear fission
Answer: Scientists are working on nuclear fusion process. Nuclear fusion is the process in which two atomic nuclei combine to form another nuclei. In the process either energy is absorbed or released due to the difference in the mass of reactants and products.
Explanation:
How many moles of KClO3 must decompose in order to produce 9 moles of oxygen gas (O2) using the following reaction by completing the t-chart below.
Answer: 6 moles of [tex]KClO_3[/tex] will be decomposed.
Explanation:
We are given:
Moles of oxygen gas produced = 9 moles
The chemical equation for the decomposition of [tex]KClO_3[/tex] follows:
[tex]2KClO_3\rightarrow 2KCl+3O_2[/tex]
By the stoichiometry of the reaction:
If 3 moles of oxygen gas is produced by 2 moles of [tex]KClO_3[/tex]
So, 9 moles of oxygen gas will be produced by = [tex]\frac{2}{3}\times 9=6mol[/tex] of [tex]KClO_3[/tex]
Hence, 6 moles of [tex]KClO_3[/tex] will be decomposed.
A gas at 100 Celsius has a volume of 33.5 L. What is its new volume after it is cooled to 25 Celsius?
Answer:
[tex]\boxed {\boxed {\sf 8.38 \ L}}[/tex]
Explanation:
We are asked to find the new volume of a gas after a change in temperature. We will use Charles's Law, which states the volume of a gas is directly proportional to the temperature. The formula for this law is:
[tex]\frac {V_1}{T_1}= \frac{V_2}{T_2}[/tex]
The gas starts at 100 degrees Celsius and a volume of 33.5 liters. Substitute these values into the formula.
[tex]\frac {33.5 \ L}{100 \textdegree C}=\frac{ V_2}{T_2}[/tex]
The gas is cooled to 25 degrees Celsius, but the volume is unknown.
[tex]\frac {33.5 \ L}{100 \textdegree C}=\frac{ V_2}{25 \textdegree C}[/tex]
We want to find the volume of the gas after it is cooled. We must isolate the variable V₂. It is being divided by 25 degrees Celsius and the inverse of division is multiplication. Multiply both sides of the equation by 25 °C.
[tex]25 \textdegree C*\frac {33.5 \ L}{100 \textdegree C}=\frac{ V_2}{25 \textdegree C}* 25 \textdegree C[/tex]
[tex]25 \textdegree C*\frac {33.5 \ L}{100 \textdegree C}= V_2[/tex]
The units of degrees Celsius cancel.
[tex]25*\frac {33.5 \ L}{100 }= V_2[/tex]
[tex]8.375 \ L = V_2[/tex]
The original measurements have 3 significant figures, so our answer must have the same. For the number we found, that is the hundredth place. The 5 in the thousandths place tells us to round the 7 up to an 8.
[tex]8.38 \ L \approx V_2[/tex]
The new volume after the gas is cooled is approximately 8.38 liters.
Which condition will probably not increase
the rate of reaction?
a. Adding water to dilute the reaction
mixture
b. Increasing the temperature
c. Adding a catalyst
d. Removing an oxide coating on a
metal
Answer:
i think A.
Explanation:
bc B. makes the molecules hight temp = move faster = more collisions = higher rate, C. it's use is to make reactions rates increase, D. somthung abt more surface area and easier collisions
Consider the reaction. 2HF(g)—H2(g)+F2(g). What is the value of Keq for the reaction expressed in scientific notation
Answer:
A). 2.1 × [tex]10^{-2}[/tex]
Explanation:
Given reaction,
2[tex]HF[/tex] (g) ⇄ [tex]H_{2}[/tex] (g) + [tex]F_{2}[/tex] (g)
The concentrations are as following;
[tex]HF[/tex] = 5.82 × [tex]10^{-2}[/tex] M
[tex]H_{2}[/tex] = 8.4 × [tex]10^{-3}[/tex] M
[tex]F_{2}[/tex] = 8.4 × [tex]10^{-3}[/tex] M
So,
[tex]K_{eq}[/tex] = [([tex]H_{2}[/tex] ) × ([tex]F_{2}[/tex])] ÷ [[tex]HF[/tex]]^2
Now,
We can determine the value of [tex]K_{eq}[/tex] by substituting the values in above formula:
[tex]K_{eq}[/tex] = [ (8.4 × [tex]10^{-3}[/tex] M) × (8.4 × [tex]10^{-3}[/tex] M)] ÷ [(5.82 × [tex]10^{-2}[/tex])^2
= 2.08 * [tex]10^{-2}[/tex]
= 2.1 × [tex]10^{-2}[/tex]
∵ [tex]K_{eq}[/tex] = 2.1 × [tex]10^{-2}[/tex]
Thus, option A is the correct answer.
A metal is treated with dilute hydrochloric
acid in a test tube. A burning match stick is brought
near the mouth of the test tube, but no sound is
heard.
Explanation:
There are certain metals that are less reactive compared to standard hydrogen electrode.
So, such metals do not release hydrogen gas in a reaction with dilute acids.
Examples of such metals are:
copper,silver,gold,platinum,mercury.
Answer:
A burning match stick is brought
near the mouth of the test tube, but no sound is
heard. That means hydrogen gas is not released in this reaction and the metal may be a less reactive metal and it is one among the above list of metals.
A published hypothesis:
A: does not need to be tested
B: becomes a scientific law
C: should be tested by the scientific community
D: is accepted by the scientific community
Answer:
C
Explanation:
I hypothesis needs to be tested to know whether it is true or not. Here is the definition:
A supposition or proposed explanation made on the basis of *limited evidence as a started point for further investigation*
Putting rock salt on the roads during a snowstorm is an example of: A. Boiling point elevation B. Vapor pressure raising C. Vapor pressure lowering D. Freezing point depression
Answer:
The correct answer is - D. Freezing point depression.
Explanation:
When rock salt is spread over snow-covered icy roads, it generates a liquid layer over it by melting from the surface thereby lowering or depression in the freezing point below the ice.
Therefore, due to this liquid layer comes into the contact with the ice present on the road and causes other ice to melts. This keeps on decreasing the volume of the ice on the road therefore, rock salts spread on the roads during a snowstorm.
On a heating curve, in which section(s) would you use the equation, Q=mCΔT, to calculate the total heat required?
on all sloped parts of the curve
on a sloped part only if under 0oC
on a sloped part only if over 100oC
only on plateaus or flat parts of the curve
Answer:
69.420 b=99699969
oil wells like the one shown here are used to obtain oil from which type of rock underground
Answer:
petroleum
Explanation:
usually found sedimentary rock.
definition: a liquid mixture of hydrocarbons that is present in certain rock strata and can be extracted and refined to produce fuels including gasoline, kerosene, and diesel oil, oil
Imagine that you move a substance from one container to another and its volume changes.
What state of matter is that substance?
gas
solid
liquid
Answer:
Gas
Explanation:
If you move a substance from one container to another and its volume changes, the substance is a gas. This is because, gases do not have fixed volume and shape; their shape and volume depend on the container used.
Answer:
I think gas.
Explanation:
Because gas doesn't have fixed shape and size.
Brainliest if answered correctly
How many Calcium (CA) atoms are in carbon tetrachloride
Answer:
What atoms are present in carbon tetrachloride?
There is 1 carbon, and 4 chlorine atoms (or chloride ions if you want to get technical). Tetra means 4 in Greek.
hope that helps❤
Answer:
there are no calcium atoms of n carbon tetrachloride
Please hurry!!!!!
this is due tomorrow morning
The periodic table is organized into groups and periods of elements. The characteristics of a certain group of elements are listed below.
Characteristics of a Group of Elements
• Is shiny
• Is solid at room temperature
• Has atoms with two valence electrons
Which of these elements is in this group?
F Lithium
G Strontium
H Aluminum
J Silicon
Answer:
Strontium is the elements which can be found in this group as it is shiny, is solid in room temperature and has atoms with two valence electrons.
Bryan is doing a chemistry lab and needs to measure exactly 3.5000 mL of water. How many significant digits are in this measurement?
1
2
3
5
Name five metal which are both dilute and memorable? class 10
use the the dot strict on the right to and the periodic table to determine the element represented.
sodium (Na)
potassium (K)
neon (Ne)
argon (Ar)
Answer:
Pottasium
Explanation:
because it is the nineteenth element
Answer:
The answer is B. Potassium.
Explanation: Potassium has 19 electrons that are organized like the image if you count the electrons on each obital. This answer is correct on edge 2020. Hope this helps!
such as water or oxygen,
All of the matter in a what
is the same?
Answer:
A water molecule consists of two atoms of hydrogen linked by covalent bonds to the same atom of oxygen. Atoms of oxygen are electronegative and attract the shared electrons in their covalent bonds.
Question 6 I need help
The answer is zero also I suggest googling the questions there is a quizlet with the answers
Given: CNO2
a) Draw the Lewis structures (Do not forget to show the calculation of the number of available valance electrons)
b) Name the geometry shape
c) Indicate the polarity (polar or non-polar)
Answer:
since there are no lone pairs on the central atom, this would be a trigonal planar molecule. It's polar because the shape of it does not cancel its polarity (you can think of it as not having a balanced electronegativity pull, since the nitrogen is pulling on one side, and the oxygens are pulling on the other. It would be nonpolar if the there were 3 Oxygens).
Sorry this take a little bit long. I was a little confused by the odd valence number
Arrange the following bonds in order of increasing ionic character:
C - H
F - H
Br - H
Na - Cl
K - F
Li - Cl
Answer:
This is the answer
C-H, Br-H, F-H, LI-CI, Na-CI, K-F
Hope this helps.
A liquid that occupies a volume of 8.2L has a mass of 5.6kg. What is the density of the liquid in kg/L
Answer:
0.68
Explanation:
This is because the formula for finding density is mass/volume. Therefore the equation becomes 5.6/8.2 giving you 0.68
What is the name of N2C14? Explain how you determined the bond type and the steps you used to determine the naming convention for the compound.
Answer:
One way to predict the type of bond that forms between two elements is to compare the electronegativities of the elements. In general, large differences in electronegativity result in ionic bonds, while smaller differences result in covalent bonds. the bonding is covalent bcz its between the most electronegative atom nitrogen and carbon .
Since the electronegativity difference between nitrogen and chlorine is not very much so chemical bonding is the only bond between them Thus the name of N2C14 is Dinitrogen Tetrachloride and there is covalent bonding in this compound
What is chemical bonding?There are two types of bonding in chemistry, one is ionic bonding while other is covalent bonding. Ionic bonding is due to the complete transfer of electron from one element to other. While the covalent bond is due to the equal sharing of electron by each element
Metals and non metals combine to form ionic bond while the element with the same electronegativity form covalent bonding.
To name this we have to see the number of element and accordingly use di, tri and the write the name of first element and then second element's name with ide
Thus the name of N2C14 is Dinitrogen Tetrachloride and there is covalent bonding in this compound
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Using dobereiner's triads, what conclusion could have been made about magnesium
Answer:
Triads were groups of 3 elements with similar chemical and physical properties. Beryllium, magnesium, and calcium are all earth alkalis found in the earth
Explanation:
