Answer:
+4
Explanation:
Oxidation number of neutral compound is 0
Oxidation number of hydrogen in methane is -1
C + (-1×4) = 0
C - 4 = 0
C = 4
Which species has 54 electrons
Answer: Neutral Xe atom
Pure substances can be classified into element and compound. Choose the
CORRECT pair(s).
I Diamond - element
II Salt - compound
III Sugar solution - element
I and Il only
I only
II and III only
III and III
How many species are known to be living on Earth?
Answer:
8.7 million species
Explanation:
Scientists have estimated that there are around 8.7 million species of plants and animals in existence.
What quantity of energy is required to heat a piece of iron wighing 1.31 g from 25.0 degrees celsius to 46.0 degrees celsius
The quantity of energy required to heat a piece of iron weighing 1.31 g from 25.0 degrees Celsius to 46.0 degrees Celsius is 2.93 calories.
What is energy?The ability or power to perform tasks, such as the ability to move an object (having a certain mass) by exerting force.
Energy can exist in many forms, including electrical, mechanical, chemical, thermal, and nuclear, and it can also change its form.
The equation q = mcT, where m is the sample mass, c is the specific heat, and T is the temperature change, can be used to determine the amount of heat acquired or lost by a sample (q).
Q = mcΔT
Q = 1.31 g x 449 x 21° C = 12.26 joule
12.26 /1 x 1 cal / 4.189= 2.93 calories
Therefore, the quantity of energy required to heat a piece of iron is 2.93 cal.
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You have 58 g of calcium chloride (CaCl2) and you need to make a 5 M solution. You know that the molecular weight of Ca is 40 and that the molecular weight of Cl is 35.5. How many liters (L) of water would you need
Answer:
0.1045 L (4 s.f.)
Explanation:
The molecular weight, [tex]M_{r}[/tex], of calcium chloride is
[tex]M_{r}(\mathrm{CaCl_{2}}) \ = \ A_{r}(\mathrm{Ca}) \ + \ 2 \times A_{r}(\mathrm{Cl}) \ = \ (40 \ + \ 2 \times 35.5) \ \mathrm{g \ mol^{-1}} \ = \ 111 \ \mathrm{g \ mol^{-1}}[/tex], where [tex]A_{r}[/tex] is the atomic weight of the respective elements.
To calculate the number of moles (n) of calcium chloride present in 58g,
[tex]n_{\mathrm{CaCl_{2}}} \ = \ mass \ \div \ molecular \ weight \ (M_{r}) \\ \\ \-\hspace{1.13cm} = \ 58g \ \div \ 111 \ \mathrm{g \ mol^{-1}} \\ \\ \-\hspace{1.13cm} = \ 0.5225 \ \mathrm{mol \ of \ CaCl_{2}}[/tex]
Since molarity, M, is defined as the number of moles (n) of the solute per liters of a solution (L), hence to get the volume (V) required to make up a 5 molar solution is
[tex]n \ = \ M \times V \\ \\ V \-\hspace{0.05cm} = \ \displaystyle\frac{n}{M} \\ \\ V \-\hspace{0.05cm} = \displaystyle \frac{0.5225 \ \mathrm{mol}}{5 \ \mathrm{mol \ L^{-1}}} \\ \\ V \-\hspace{0.05cm} = \ 0.1045 \ \mathrm{L}[/tex]
It takes 60 mL of 0.20 M of sodium hydroxide (NaOH) to neutralize 25 mL of carbonic acid (H2CO3) for the following chemical reaction:
2 NaOH + H2CO3 → N2CO3 + 2 NaOH
The concentration of the carbonic acid is _____.
A) 0.48m
B) 0.10m
C) 0.96m
d)0.24m
If It takes 60mL of 0.20M of sodium hydroxide (NaOH) to neutralize 25 mL of carbonic acid ([tex]H_2CO_3[/tex]), then the concentration of the carbonic acid is 0.24M
The reaction between NaOH solution and [tex]H_2CO_3[/tex] is written below
[tex]2NaOH + H_2CO_3 \rightarrow Na_2CO_3 + 2H_2O[/tex]
Volume of NaOH, [tex]V_B[/tex] = 60 ml
Volume of [tex]H_2CO_3[/tex], [tex]V_A=25 ml[/tex]
Molarity of [tex]H_2CO_3[/tex], [tex]C_A=?[/tex]
Molarity of NaOH, [tex]C_B=0.20M[/tex]
Number of moles of [tex]H_2CO_3[/tex], [tex]n_A=1[/tex]
Number of moles of NaOH, [tex]n_B=2[/tex]
The mathematical equation for neutralization reaction is:
[tex]\frac{C_AV_A}{C_BV_B} =\frac{n_A}{n_B}[/tex]
Substitute [tex]C_B=0.2 M[/tex], [tex]n_A=1[/tex], [tex]n_B=2[/tex], [tex]V_B[/tex] = 60ml, and [tex]V_A=25 ml[/tex] into the equation above in order to solve for [tex]C_A[/tex]
[tex]\frac{C_A \times 25}{0.2 \times 60}=\frac{1}{2} \\\\50C_A=12\\\\C_B=\frac{12}{50} \\\\C_B=0.24M[/tex]
Therefore, the concentration of the carbonic acid is 0.24M
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Which are the two key factors that affect the rate of weathering of rocks?
Select 2.
A Climate
B Rock Type
C Bedrock
Answer:
A and B.
Explanation:
Climate:
High temperatures and greater rainfall increase the rate of chemical weathering. Lower temperatures can break rocks to by freezing water inside of a rock cracks. When it freezes it expands the water and forces the crack of the rock to expand.
Rock Type:
Certain types of rock are very resistant to weathering. Igneous rocks, especially intrusive igneous rocks such as granite, weather slowly because it is hard for water to penetrate them. Other types of rock, such as limestone, are easily weathered because they dissolve in weak acids.
Oxygen-15 decays through the release of a beta particle. Draw what the nucleus would look like after a beta particle is emitted. What element does it become?
When oxygen -15 nucleus undergoes beta emission, it is transformed into Fluorine - 15 nucleus.
Beta decay is said to occur when a neutron is converted to a proton. This process leads to the emission of en electron. The neutron - proton ratio decreases and the atomic number of the daughter nucleus is greater than that of the parent nucleus by one unit.
Hence, when oxygen -15 nucleus undergoes beta emission, it is transformed into Fluorine 15 nucleus.
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soaps do not work well in hard waters. But they can still be effected it large quantities of soap are added to water. Explain why.
Why do nonmetal atoms share electrons in covalent bonds
Answer:
pairs of electrons
Explanation:
covalent bondin occurs when pairs of electrons are shared by atoms.... nonmetal will readily form covalent bonds with other nonmetal in order to obtain stability.
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Which two types of air masses would likely form a subtropical jet stream?
Warm and cool air masses meeting near the North Pole
Cool and warm air masses meeting near the equator
Multiple warm air masses meeting near the equator
Two or more cool air masses meeting near the South Pole
Answer:
Give person above me brainliest
Explanation:
How do many types of cells, like bacteria, reproduce?
Answer:
cells like bacteria are bisexual so they split and their offspring is 100 percent like the parent and this process happens over and over
Explanation:
The diagram below shows the reaction between iron oxide and carbon that produces iron and carbon dioxide. The reaction takes place in a closed system. What is true about the carbon atoms in the reaction? A. The mass of carbon atoms in the reactants is the same as the mass of carbon atoms in the products. B. The total mass of the carbon atoms is the same as the total mass of the iron atoms. C. The mass of the carbon atoms increases between the reactants and the products of the reaction. D. The total mass of the carbon atoms is the same as the total mass of the oxygen atoms.
Answer:
A
Explanation:
The trick here is to know what the conservation of mass means.
It means that no matter what happens and how much change there is, the mass of the carbons on the reactants = the mass of the carbons on the products.
That's exactly what A says.
which type of element pairs can form ionic bonds
Answer:
Between metal and nonmetal ion's
Explanation:
for example, sodium (Na),a metal and a chloride (Ci
does the following atomic model of a chemical reaction correctly demonstrate the law of conversation of matter why or why not
plzzz help
Answer:
Yes
Explanation:
You can tell because there are 2 moles of H2 on the reactants side and 1 mole of O2, and on the products side we see the same amount, meaning that no moles of H2 or O2 were added or destroyed, meaning that it follows the law of conservation of matter.
Can I get some help
Answer:
I'm afraid not, the image is too blurry
yesss☺️
sorryyyyyy
sorryyyyy
what will happen to a person who doesn't recognize authors and even citing proper sources?
it will be called verbatim plagiarism, also called direct plagiarism
pls ansswerrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrr
Answer: Its C, c is a solid state
the answer :
Hi there !
The answer is "C"
; due to the intermolecular forces of attraction
Triple covalent bond can be formed between:
a)C&H
b) N&S
c) C & S
d) C&O
e) O & S
Answer choices are A. Constant speed
B. Stopped
C.Moving sideways
D.Accelerating
what happens when you combine hydroxide, chlorine, and 2 drops of h2o
Answer:
Chlorine will react in water to form hypochlorous acid, which can then dissociate into hydrogen and hypochlorite ions, according to Eqn (1). This reaction is very important, as the disinfecting power of HOCl, hypochlorous acid, is about 40–80 times that of OCl−, hypochlorite.Explanation:
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A bottle rocket takes off with a speed of 13 m/s and is angled 55 degrees above the horizon. What is the Y component of the velocity ?
Answer:
10.53m/s
Explanation:
Initial velocity: 13m/s
Angle of projection: 55deg
Y-component of velocity is given as usin⌀
Plugging in, we get
= 13 * sin(55deg)
= 13 * 0.81
= 10.53
⇒ 10.53m/s
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In an experiment, equal amounts of water and sand were heated under a lamp. The initial and final temperatures of each were recorded. A partial record of the temperature is shown.
Experimental RecordSubstance Initial Temperature Final Temperature
Sand 20 °C 26 °C
Water 20 °C ?
Which statement about the final temperature of water is correct?
A. It will be less than 26 °C as sand has a relatively higher specific heat than water.
B. It will be less than 26 °C as water has a relatively higher specific heat than sand.
C. It will be more than 26 °C as sand needs relatively higher energy than water to raise its temperature.
D. It will be more than 26 °C as water needs relatively higher energy than sand to raise its temperature.
hi have a nice day
will be less than 26 °C as water has a relatively higher specific heat than sand.
Explanation:
The specific heat of a substance is the amount of heat energy absorbed by one unit of mass of the substance when its temperature increases one unit.
From that, you can derive the equation for the specific heat of a substance:
specific heat = heat / (mass × ΔT)
Thus, assuming that all the heat provided by the lamp to both samples is the same and, as given, the amount (mass) of both samples is also the same, you have that the specific heat of the samples will be:
specific heat = constant / ΔT
So, specific heat and ΔT are inversely related.
It is known that water has a higher specific heat than sand (that is why the sand on the shore of a beach is, during the day, hotter than the water and your feet get burned when you walk on a sandy beach on a sunny day
The discrepancy between results given by the van der Waals equation and the ideal gas law will increase as:
This question is recalling the behavior of real gases in contrast to ideal gases, defined by the van der Waals equation and the ideal gas law respectively, and a reason behind the increasing discrepancy is required.
In such a way, we can start by considering the attached picture in which the choices are shown and clearly, the answer is "as the polarity of the molecules increase".
The aforementioned can be explained with the concept of intermolecular forces, because ideal gas theory states that ideal gas molecules do not interact one to another, and, as the polarity of the molecules increase, these intermolecular forces increase their frequency and strength, and will lead to the formation of associations, which fail to be numerically modelled by simple equations of state such as van der Waals, Redlich-Kwong, Peng-Robinson, etc,.
These associations are, of course, thoroughly neglected by the ideal gas law whereas the ones included in the van der Waals equation, which are not the most reliable, merely attempt to approach this phenomenon, which cause the mentioned discrepancy. As an additional data, robust equations of state, such as CPA (cubic plus association) are able to provide reliable results when working with highly polar gases but turn out really tough to work with due to its mathematical complexity.
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https://brainly.com/question/13423552https://brainly.com/question/13201335Which best explains why a person can tell the difference between a whisper and a yell?
O Sound waves turn into chemical signals that indicate certain sounds.
Different vibrations in the ear cause the bras o interpret different sounds.
The fluid in the cochlea picks up electrical signals for the intensity of sound.
The eyes see what is making the noise and help the brain process the sound.
Answer:
The difference is the louder the sound the bigger the waves and your ears collect the sound waves and brings it to you brain
Explanation:
Answer:
Hey! The correct answer is D.) Different vibrations in the ear cause the brain to interpret different sounds.
Explanation:
I got a low score on the test but yeah I got that one correct so It's D
Michelle is trying to find the average atomic mass of a sample of an unknown
element. She finds that her sample contains 59.34% of an isotope with a mass of
113.6459, while the rest of the sample is an isotope with a mass of 115.8488. What
is the average atomic mass of her sample? Please round your answer to 0.01 amu.
The average atomic mass of her sample is 114.54 amu
Let the 1st isotope be A
Let the 2nd isotope be B
From the question given above, the following data were obtained:
Abundance of isotope A (A%) = 59.34% Mass of isotope A = 113.6459 amuMass of isotope B = 115.8488 amuAbundance of isotope B (B%) = 100 – 59.34 = 40.66%Average atomic mass =?The average atomic mass of the sample can be obtained as follow:
[tex]Average \: atomic \: mass \: = \frac{mass \: of \: A \times A\%}{100} + \frac{mass \: of \: B \times B\%}{100} \\ \\ Average \: atomic \: mass \: = \frac{113.6459\times 59.34}{100} + \frac{115.8488\times 40.66}{100} \\ \\ Average \: atomic \: mass \: = 114.54 \: amu \\ \\ [/tex]
Thus, the average atomic mass of the sample is 114.54 amu
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PLEASE PLEASE HELP! CHEM!
Answer:
0.963158 maybe just put 0.96
Explanation:
732mmhg to atm is 0.963158 i looket it up sorry if I am wrong
A quantity of HCL ( 1.5*10⁻³ M) is added to water at 25°C to increase the hydrogen ion concentration from 1*10⁻⁷ to 1.5* 10⁻³ moles per liter. What is the new hydroxyl ion concentration?
WHICH ONE?????????????????? Brainlest
Answer:
I believe it would be C, The number of atoms in the reactants is equal to the number of atoms composing the products
Explanation:
hope this helps! :D
have a miraculous day!! <3
Answer:
The number of atoms in the reactants is equal to the number of atoms composing the products
if one gram of sulphur dioxide contains x molecules what will be the number of molecules in 1g of methane
The ratio of molecules in sulphur dioxide and methane will be the same as the ratio of their moles. So, first of all we should find out the number of moles of sulphur dioxide in 1 gram of sulphur dioxide in 1 gram of sulphur dioxide, and the number of moles of methane in 1 gram of methane. This can be done as follows :
(i) The molecular formula of sulphur dioxide is [tex]SO_{2}[/tex]
So, [tex]1[/tex] mole of [tex]SO_{2}[/tex] = [tex]Mass[/tex] [tex]of[/tex] [tex]2'O'[/tex]
[tex]=32+2*16[/tex]
[tex]= 64[/tex] grams
Now, [tex]64g[/tex] of sulphur dioxide [tex]= 1[/tex] mole
So, [tex]1g[/tex] of sulphur dioxide = [tex]\frac{1}{64}[/tex] mole
Thus, we have [tex]\frac{1}{64}[/tex] mole of sulphur dioxide and it contains molecules in it. Now, since equal moles of all the substance contain equal number of molecules, therefore, [tex]\frac{1}{64}[/tex] mole of methane will also contain x molecules of methane.
(ii) Molecular formula of methan is [tex]CH_{4}[/tex]
So, 1 mole of [tex]CH_{4}[/tex] = Mass of C + Mass of 4 H
[tex]=12+4*12[/tex]
Now, 16g of methane = 1 mole
So, 1 g of mathane = [tex]\frac{1}{16}[/tex] mole
We know that:
[tex]\frac{1}{64}[/tex] mole of methane contains = x molecules
So, [tex]\frac{1}{16}[/tex] mole of contains will contain =[tex]\frac{x*64}{16}[/tex] molecules
=[tex]4x[/tex] molecules