Answer:
Explanation:
mostly empty space
An exothermic reaction releases 13,450J of heat. How many calories of energy are released? A) 5 56,274 calories B)1,244 caloriesC) 134,500 caloriesD) 3,215 calories
Answer:
The correct option is;
D) 3,215 calories
Explanation:
Here we are required to convert 13,450 J to calories
1 calorie is the amount of heat required to raise the temperature of 1 gram of water by 1°C
Therefore, 1 calorie = 4.184 Joules
Hence, 1 Joule = 1/4.184 calorie for which we have;
13,450 J = 13,450 × 1/4.184 calories = 13,450/4.184 calorie
13,450 J = 3,214.63 calories
Rounding up to the nearest whole number, we have;
13,450 J ≈ 3,215 calories.
In the reaction N2 + 3H2 - 2NH3, how many
grams of H, are needed to produce exactly I mole
of ammonia?
A. lg
B. 2g
C.3g
D.4g
Answer:
B. 2g
Explanation:
So first you have to find the mole to mole ratio then convert it to grams if that makes sense. So the mole to mole ratio is 2 ammonia to 3 hydrogen gas. So then after you do that conversion you can solve for grams then. Sorry I am not that great at explaining.
1. What are the trends for atomic size across a period and down a group for the
main group elements?
2. Draw the following Lewis structures:
a) ammonium ion b) sulfur trioxide c) hydrogen cyanide
3. Using formal charge formula (or electronegativity differences), to determine
the following the best structure, OCS, COS or CSO.
Answer:
Here's what I get
Explanation:
1. Trends in atomic size
Atomic size tends to decrease from left to right across the Periodic Table.
You are adding one electron at a time. the electrons repel each other, so the size should increase.
You are also adding a proton to the nucleus. The additional attraction should pull the electrons closer to the nucleus.
The nuclear pull wins, so the atoms get smaller from left to right
Atomic size increases from top to bottom of a Group.
You are adding electrons to an extra shell, so the size should increase.
You are also adding protons to the nucleus, so the size should decrease.
The size of the outer shell wins, so the atomic size increases going down a Group.
2. Lewis structures
(a) Ammonium ion
N is the central atom. The N atom has the positive charge.
(b) Sulfur trioxide
S is the central atom, with a double bond to each of the three O atoms.
(c) Hydrogen cyanide
C is the central atom, with a triple bond to the N atom.
3. COS
The best structure is that of O=C=S. It has no formal charges.
The Lewis structures for the other arrangements have formal charges.
The correct answers of this question is given below.
1. The atomic size increases going down a Group.2. (a) Ammonium ion : The N atom has the positive charge. (b) Sulfur trioxide : Having double bond to each of the three O atoms. (c) hydrogen cyanide : Having a triple bond to the N atom.3. COS and it has no formal charges What is Periodic table?A table in which the chemical elements are arranged in order of increasing atomic number.A periodic table has 118 known elements The chemical elements are arranged from left to right and top to bottom in order of increasing atomic number.What is the explanation for this answers?1. Trends in atomic size : Atomic size tends to decrease from left to right across the Periodic Table.You are adding one electron at a time. the electrons repel each other, so the size should increase.You are also adding a proton to the nucleus. The additional attraction should pull the electrons closer to the nucleus.The nuclear pull wins, so the atoms get smaller from left to right.Atomic size increases from top to bottom of a Group.Adding electrons to an extra shell, so the size should increaseAdding protons to the nucleus, so the size should decrease.The size of the outer shell wins, so the atomic size increases going down a Group.2. Lewis structures :
(a) Ammonium ion : N is the central atom. The N atom has the positive charge. (b) Sulfur trioxides : S is the central atom, with a double bond to each of the three O atoms.(c) Hydrogen cyanide: C is the central atom, with a triple bond to the N atom3. COS
The best structure is that of O=C=S. It has no formal charges.The Lewis structures for the other arrangements have formal charges.Learn more about atomic size below,
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If a buffer has an initial pH of 6.34 and the acid has a Ka of 3.46 × 10-4, what is the ratio of conjugate base to weak acid in the buffer system?
Answer: The ratio of conjugate base to weak acid in the buffer system is 758 : 1
Explanation:
The dissociation constant for acid = [tex]K_a=3.46\times 10^{-4}[/tex]
pH = 6.34
First we have to calculate the value of [tex]pK_a[/tex].
The expression used for the calculation of [tex]pK_a[/tex] is,
[tex]pK_a=-\log (K_a)[/tex]
Now put the value of [tex]K_a[/tex] in this expression, we get:
[tex]pK_a=-\log (3.46\times 10^{-4})[/tex]
[tex]pK_a=3.46[/tex]
Now we have to calculate the ratio of conjugate base to weak acid in the buffer system
Using Henderson Hesselbach equation :
[tex]pH=pK_a+\log \frac{[\text {conjugate base}]}{[Acid]}[/tex]
Now put all the given values in this expression, we get:
[tex]6.34=3.46+\log \frac{[\text {conjugate base}]}{[Acid]}[/tex]
[tex]\frac{[\text {conjugate base}]}{[Acid]}=758[/tex]
Therefore, the ratio of conjugate base to weak acid in the buffer system is 758: 1
Answer:
A. 1:0.46
Explanation:
I took the test
1-Which reaction shown below is carried out by nitrifying bacteria? I will mark you as brainlist
Choose:
A.{ammonium} to {nitrate}
B.{nitrate} to {nitrogen gas}
C.{nitrogen gas} to{ammonium}
Answer:
ammonium to nitrate.
Explanation:
they tie em together
Inside the retina of our eyes are receptors called rods and cones. Rods measure the brightness we see and cones determine _____.
A) the color we see
B) the white we see
C) the dimness we see
D) the loudness we hear
Which of the following best summarizes photosynthesis?
A.A chemical reaction involving nitrogen and other atmospheric gases
B.An adaptation of plants that allows them to add nutrients to the soil
C.A process by which plants produce sugar using the energy of sunlight
D.An exchange of gases between animals and the air or water of their habitat
Answer:
c. a process by which plants produce sugar using energy of sunlight
Describe the interactions with the Sun, Earth and Moon system that result in Lunar Cycle / Phases.
Answer: The tides are another interaction in the sun-earth-moon system. The tides happen because the moon and sun pull on the oceans, causing them to rise and fall each day. The moon has a bigger effect than the sun because it is closer. The angle of the sun as the earth orbits over the course of a year causes the seasons.
Explanation:
Question 3 of 10
5 Points
Match the approximate percentage of the world's water to where it is stored.
Salt water
97 percent
Ice caps and
glaciers
2 percent
Fresh liquid
water
1 percent
Answer:
salt water 97%
fresh water 1%
frozen 2%
Explanation:
What is the similarity between speed and vilocity
can somebody help me name these organic compound plz
Answer:
A. 3–Ethyl–2–methylpentane.
B. 3–Ethyl–1,5,5–trimethylcyclohexene.
Explanation:
To name the compound, we must observe the following:
1. Locate the longest continuous carbon chain. This gives the parent name.
2. Identify the substituent groups attached.
3. Locate the position of the substituent groups by giving them the lowest possible low count alphabetically.
4. Combine the above to name the compound.
Now let us name the above compounds
For compound (A)
1.The longest chain is carbon 5 i.e pentane.
2. The substitute attached are:
Ethyl => CH2CH3
Methyl => CH3
3. Ethyl comes before methyl alphabetically. But considering the structure of the compound, ethyl assume same position from either side of the compound. Therefore, we'll consider the lowest possible count for methyl. Therefore, their position is given below:
Ethyl => CH2CH3 => carbon 3.
Methyl => CH3 => carbon 2.
4. The name of the compound is:
3–Ethyl–2–methylpentane.
Compound B.
This is a cyclic structure.
1. The parent name is cyclohexene.
2. The substitute groups attached are:
Ethyl => CH2CH3
Methyl => CH3
3. Since the compound is unsaturated, the functional group is the double bond. Hence, we shall start our counting from the double bond and also considering alphabetical order of the substituent.
Please note methyl (CH3) appears three times.
Ethyl => CH2CH3 => carbon 3
Methyl => CH3 => carbon 1, 5 and 5.
4. The name of the compound is:
3–Ethyl–1,5,5–trimethylcyclohexene
CAN SOMEONE HELP ME?!?! IM CONFUSED
Answer: Solar winds have an influence all the way to about 160 AU from the Sun. About how many kilometers is that?
24,000,000,000 km
48,000,000,000 km
240,000,000,000 km
480,000,000,000 km
Explanation:
Which formula represents an alkane?
1.
C2H2
2.
C2H4
3.
C3H4
4.
С3Н8
Answer: Option 4) is correct.
Explanation: It is correct because alkanes have a general formula CnH2n+2. So, all we need to do is substitute and find out how many hydrogens are needed to make the formula an alkane. I am not really good at explaining. I am sorry If I confused you.
Alkanes are the organic compound which has general formula [tex]C_{n}H_{2n +2}[/tex] which satisfies the formula [tex]C_{3}H_{8}[/tex]. Hence [tex]C_{3}H_{8}[/tex] represents an alkane.
AlkaneAlkanes are simplest saturated hydrocarbon. Alkanes are also known as paraffins wax. Alkanes which contains only carbon and hydrogen atoms.
General Formula of AlkaneThe general formula of alkane is [tex]C_{n} H_{2n + 2}[/tex] where n = 1, 2, 3, 4.......
Consider Option 1, [tex]C_{2}H_{2}[/tex] here n = 2 now put the value of n in above formula, we get: [tex]C_{2} H_{2 \times 2 + 2}[/tex] = [tex]C_{2} H_{4 + 2}[/tex] = [tex]C_{2} H_{6}[/tex] , so option 1 does not satisfies the above formula. Hence it is incorrect. Consider Option 2, [tex]C_{2} H_{4}[/tex] here n = 2 now put the value of n in above formula, we get: [tex]C_{2} H_{2 \times 2 + 2} = C_{2} H_{4 + 2} = C_{2} H_{6}[/tex], so option 2 does not satisfies the above formula. Hence it is incorrect. Consider Option 3, [tex]C_{3} H_{4}[/tex] here n = 3 now put the value of n in above formula, we get: [tex]C_{3} H_{2 \times 3 + 2} = C_{3} H_{6 + 2} = C_{3} H_{8}[/tex], so option 3 does not satisfies the above formula. Hence it is incorrect. Consider Option 4, [tex]C_{3} H_{8}[/tex] here n = 3 now put the value of n in above formula, we get: [tex]C_{3} H_{2 \times 3 + 2} = C_{3} H_{6 + 2} = C_{3} H_{8}[/tex], so option 4 satisfies the above formula. Hence it is correct.Thus, from the above conclusion we can see that option 4 [tex]C_{3}H_{8}[/tex] represents an alkane.
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Static electricity is
a closed conducting path
when electrons move easily through objects
build up of electrical charges by friction
Mosquitoes lays eggs that must hatch in water. The young, called larvae live their first few days in water
Which sentence best describes where you will most likely find mosquitoes and their eggs during the dry season in the Florida Everglades?
A.They will be spread out because water is everywhere.
B.They will be mainly in one area because water is everywhere
C. They will be in fewer areas because water is scarce
D. They will be everywhere because water is scarce.
Answer:
Explanation:
I believe he is C
As the kinetic energy of particles of matter increase, the distance between the particles?
What does a dissolved salt look like?
A. The salt crystals are surrounded by water molecules.
B. The salt crystals separate into salt molecules in the water.
C. The salt separates into ions that settle to the bottom
D. The ions in the salt are surrounded by water molecules.
Answer:
I want to say your answer is B)
The answer is D because the ions in the salt will be surrounded by water molecules
Dissolution in water occurs as a result of ionic interactions. This means that the ions (charged atoms) of the solute has to interact with the ions of water for the solute to dissolve. Based on this principle, only polar compounds can dissolve in water.
According to this question, salt is polar because it contains positive (+) and negative (-) ions. Hence, when placed in water, these ions will interact with the ions of water i.e. H+ and OH-. This causes dissolution of salt in water to form salt solution.
Hence, a dissolved salt will look like "ions in the salt are surrounded by water molecules".
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I need the correct answer
Answer:
d.
Explanation:
They can be spread through contaminated surfaces.
Answer:
d
Explanation: pathogens csnnot be spread be sontaminated surfesec
What type of bond is formed during dehydration synthesis?
O A
carbon bonds between amino acids
B.
carbon bonds between carbohydrates
C. hydrogen bonds between lipids
O D. peptide bonds between amino acids
A carbon bond between the amino acids is formed in a dehydration reaction. So the correct option is A.
What is a dehydration reaction?
A reaction where two smaller molecules are combined in a chemical manner by the removal of an element from each of these molecules is called a dehydration reaction. Organic compounds are classified on the basis of structure. They are classified as aliphatic and aromatic compounds. Different kinds of chemical reactions are involved in the formation of new compounds when there is a change in bonding between the atoms.
There are some chemical reactions that form a molecule and some only show a displacement or substitution of atoms. There are synthesis or combination reactions that involve a combination of two substances to form one molecule.
On the other hand, there are decomposition reactions in which one substance decomposes to form more than one substance. There are displacement reactions which can be single or double displacement. They involve the displacement of one or more components of compounds among each other. Addition, substitution, rearrangement, elimination, and oxidation-reduction reactions are some of the common organic reactions.
Therefore, the correct option is A.
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60.0 g of NH Cl are dissolved in 100 grams of water at 60.0° C. This solution is
A
supersaturated
B
saturated
С
unsaturated
D
none of the above
Answer:
B) is the correct answer
NEED ASAP WILL MARK BRAINLIEST ON TIMER
A student determines that she used 0.0665 mol of sodium hydroxide (NaOH) to completely titrate 25.00 mL of sulfuric acid solution (H2SO4). What is the molarity of the sulfuric acid?
0.00131 M
0.00262 M
1.31 M
2.62 M
A student determines that she used 0.0665 mole of sodium hydroxide (NaOH) to completely titrate 25.00 mL of sulfuric acid solution. The molarity of the sulfuric acid is 1.31 M. Therefore, option C is correct.
What is molarity?Number of moles of solute per liter of solution is known as molarity.
The balanced chemical equation for the reaction between sodium hydroxide and sulfuric acid is:
2 NaOH + H₂SO₄ → Na₂SO₄ + 2 H₂O
According to the balanced equation, one mole of sulfuric acid reacts with two moles of sodium hydroxide. Therefore, the number of moles of sulfuric acid in the titrated solution can be calculated as:
moles of H₂SO₄ = (moles of NaOH) / 2
moles of H₂SO₄ = 0.0665 mol / 2
moles of H₂SO₄ = 0.03325 mol
The volume of the sulfuric acid solution used in the titration is 25.00 mL, which is equivalent to 0.02500 L. The molarity (M) of the sulfuric acid can be calculated as:
Molarity of H₂SO₄ = moles of H₂SO₄ / volume of H₂SO₄ solution in liters
= 0.03325 mole / 0.02500 L
= 1.31 M
Thus, option C is correct.
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To measure the volume of a washing machine, use:
liters
kiloliters
kilograms
tons
Answer:
kg
Explanation:
Answer:
You should use tons or kilograms because a washing machine is very heavy.
(Hope this helps)
A 350. mL air sample collected at 35 degrees C has a pressure of 556 mm Hg.
What pressure will the air exert if it is allowed to expand to 425 mL at 57 degrees
C? Show your work in the space below.
Answer:
485 torr
Explanation:
Explanation:
We can solve this equation using the combined gas law:
P1V1/T1=P2V2/T2
Remember, always use the absolute (Kelvin) temperature when working with gas equations.
The temperature conversions are
T1=C+273=35o+273=308K
T2=57C+273=330K
Since we're trying to find the final pressure, let's rearrange this equation to solve for
P2:
P2=P1V1T2/T1V2
Our known values:
P1= 550 torr
V1=350mL
T1=308K
V2=425"mL
T2=330K
Let's plug these into the equation to find the final pressure:
The final pressure after it is subjected to these changes is thus 485torr
A gas has a volume of 3.00 L at 65.0 C. The same gas has a volume of 11.4 L at 105 C and 1725 mmHg. What was the original pressure of the gas?
According to plate tectonics, the continents.
do not move at all
are drifting on a sea of magma
will one day be joined together
"float' on top of the crust
Answer:
are drifting on a sea of magma.
Explanation: Please mark brainliest.
what two factors does elastic potential energy depend upon
Answer: Spring constant k as well as the distance stretched
Explanation:
Elastic potential energy is Potential energy stored as a result of deformation of an elastic object, such as the stretching of a spring. It is equal to the work done to stretch the spring, which depends upon the spring constant k as well as the distance stretched.
Which of the following statements is true?
Sound vibrations are changed into electrical impulses by the eardrum.
It is dangerous to listen to sounds over 160 dBs.
High-pitched sounds have low frequencies.
All of the above.
Answer:
all of the above!! :)))
Explanation:
Which of the following is most likely a homogeneous mixture?
O A. A tossed vegetable salad
B. Chunky peanut butter
O C. Chocolate chip cookies
OD. A vanilla milkshake
Answer:
D)A vanilla milkshake
Explanation:
a put question in screen shot
Answer:maybe 2
Explanation:
Answer:
2
Explanation:
EMERGENCY: I WILL FAIL: PLS HELP WILL MARK BRAINLIEST JUST PLS HELP
Answer:
condensation: moisture builds up on window; dew forms on blades of grass
deposition: snow is made inside a cloud; frst froms on window?
Explanation:
