Like in a cat's eye, the human pupil changes shape in response to changes in
the environment. What is the most likely function of this structure?
A. To allow humans to read
B. To allow humans to see clearly in different levels of light
C. To allow humans to see shades in color
D. To allow humans to see at varying distances
Answer:
B.
Our pupils contract and expand depending on the amount of light at any given time in order to avoid being blinded and to see better in the darkness.
When naming bases, you add ___ to the end
Answer:
hydroxide ion
Explanation:
because base produce hydroxide ion when dissolved in water
how many grams of Na2SO4, (molar mass =142.0 g/mol) are there in 15 mL of 0.50 m Na2SO4 solution?
Answer:
1.1 g Na2SO4
Explanation:
First convert mL to L. Then multiply by the Molarity to get moles, then multiply by the molar mass to get grams.
15 mL x 1 L x 0.50 mol Na2SO4 x 142 g = 1.1 g
10^3 mL 1 L mol Na2SO4
In a formula unit, there are 48 gram of Na2SO4 atoms of each element. In terms of molar mass (gram mass unit): 45.98 g Na2SO4 in total 142.04 g sodium sulphate
How many moles of Na2SO4 are there?A mole of sodium sulphate is created when two moles of sodium (45.98 g), one mole of sulphur (32.06 g), and four moles of oxygen (64.00 g) are combined (142.04 g).
The atomic mass of sodium sulphite is equal to 10 moles times the molecular mass, or 1260 grams. Consequently, 1260 grams are the mass of 10 moles of sodium sulphite (Na2SO4).
We first obtain the atomic weights of the different elements in a periodic table in order to compute the molar mass of a molecule. Then, we multiply the total number of atoms by each one's atomic mass. Finally, we calculate the molar mass by combining all the atomic masses.
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One liter of helium gas has a mass of 2.3 grams at STP. True or false
Answer:
n=V/Vm
n=1/22.4
n=0.044 moles He
m=n×M
m=0.044×4
m=0.178 g False
Which of these actions increases enthalpy in the air molecules of the Earth's
atmosphere?
A. The air being heated by the sun
B. Trees being planted in the rain forests
C. Carbon dioxide being taken in by plants during photosynthesis
D. People breathing in oxygen
HELP PLS
Answer:
The air being heated by the sun
Explanation:
Just took the quiz
Answer:
The answer is A (the air being heated by the sun)
Explanation:
A P E X
Is anyone good at chemistry if so can someone help me please ?
(NO LINKS)
This requires familiarity with the different theories (or concepts) of acids and bases.
On the Arrhenius concept, an acid is a substance that produces an H⁺ ion in water such that the H⁺ concentration increases, and a base is a substance that produces an OH⁻ ion in water such that the OH⁻ concentration increases.
On the Brønsted–Lowry concept, an acid is a substance that donates a proton (which is basically an H⁺ ion) in a solvent, and a base is a substance that accepts a proton in a solvent.
On the Lewis concept, an acid is a substance that accepts an electron pair in a solvent, and a base is a substance that donates an electron pair in a solvent.
The concepts become progressively broader, i.e., the Arrhenius concept is the most restrictive and the Lewis concept is the least restrictive. As a corollary, an Arrhenius acid or base is also both a Brønsted–Lowry acid or base and a Lewis acid or base, respectively; a Brønsted–Lowry acid or base is not necessarily an Arrhenius acid or base, but an Arrhenius acid or base is also a Lewis acid or base, respectively. And finally, a Lewis acid or base may not necessarily be either an Arrhenius or a Brønsted–Lowry acid or base.
So, with the above concepts in mind, we can match the statements in column A with the type of acid or base in column B:
[tex]\begin{center}\begin{tabular}{ c c } 1 & Bronsted Lowry acid \\ 2 & Bronsted Lowry base \\ 3 & Arrhenius acid \\ 4 & Arrhenius base \\ 5 & Lewis base \\ 6 & Lewis acid\end{tabular}\end{center}[/tex]
PLEASE HELP ME PLEASEEE AND QUICK.
NO TROLL ACCOUNT AND POSTING A LINK TO NO WHERE, PLEASE. DONT. UR WASTING MY TIME.
SOMEONE PLEASE BE NICE.
Please answer ALL THREE if u can, thank you so so so so much!!!
Answer:
Eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee
Explanation:
List 4 significant problems with nuclear power plants.xx
Answer:
Cost.
Weapons Proliferation Risk.
Meltdown Risk.
Mining Lung Cancer Risk.
Explanation:
Hope this helped!!!
A 5.0 L air sample at a temperature of -50°C has a pressure of 800.00 mmHg. What
the new pressure if the temperature is raised to 100°C and the volume expands to 7.0
L?
Answer:
956 mmHg
Explanation:
The combined gas law states that P1V1/T1 = P2V2/T2 when moles of gas are constant. We're looking for P2, so solve all of that for P2. Make sure you convert your temperatures to Kelvin by adding 273 to the Celsius temperatures.
P2 = P1V1T2/T1V2
P1 = 800.00 mmHg
V1 = 5.0 L
T2 = 100 + 273 = 373 K
T1 = -50 + 273 = 223 K
V2 = 7.0 L
P2 = (800.00 mmHg)(5.0 L)(373 K) / (223 K)(7.0 K) = 956 mmHg
which of the following affect the discharge of ions in electrolysis
Answer:
Discharge of ions during electrolysis is affected by, current apllied, the time of electrolysis, electrode type, posiiton of metal in electrochemical.
Explanation:
Convert 25.4 grams of barium phosphate, Ba3(PO4)2 to formula units.
How much water would I need to add to 700 mL of a 2.7 M KCl solution to make a 1.0 M solution?
Answer:
[tex]1190\ \text{mL}[/tex]
Explanation:
[tex]M_1[/tex] = Initial Concentration of KCl = 2.7 M
[tex]V_1[/tex] = Volume of KCl = 1 M
[tex]M_2[/tex] = Final concentration of KCl = 1 M
[tex]V_2[/tex] = Amount of water
We have the relation
[tex]M_1V_1=M_2V_2\\\Rightarrow V_2=\dfrac{M_1V_1}{M_2}\\\Rightarrow V_2=\dfrac{2.7\times 700}{1}\\\Rightarrow V_2=1890\ \text{mL}[/tex]
The amount of water that is to be added is [tex]1890-700=1190\ \text{mL}[/tex].
I need help
Balance the chemical equation
Answer:
Iwill add 2 for Na and 2 for NaCl so the answer is "C"
form a belt between Mars and Jupiter.
A)
Asteroids
B)
Comets
C)
Meteors
D)
Stars
Answer:
A
Explanation:
A student performed an experiment in which 10 mL of a strong acid was placed on a sample of limestone. Bubbles formed where the acid touched the limestone. After 20 minutes, the bubbling stopped and the surface of the limestone appeared unchanged. What is an observation that suggests a chemical reaction did in fact take place between the acid and the limestone?
a) The limestone appeared to be unchanged.
b) The acid had to be prepared beforehand.
c) Bubbles formed where the acid and limestone touched.
d) None of the above
Answer:
Answer is D, None of the above :)
Explanation:
3.
Why do you suppose internet service costs a lot of money?
Answer:
Why does internet cost so much? Equipment and installation: One of the main reasons for internet prices to run high is the cost of equipment and installation in new service areas. Fiber optic cables are expensive, so fiber optic internet providers may have higher prices to recoup the costs of installing new lines.Apr 21, 2021Explanation:
What is the smallest ph possible
Answer: -3.6
Explanation:
The lowest pH of -3.6 is the lowest known for any water in the environment
Consider the system below at equilibrium at 200oC. 2Cl2 (g) + 2H2O (g) + heat ↔ 4HCl (g) + O2 (g) Which response contains all the stresses listed that will result in a shift of equilibrium so that more HCl is produced when equilibrium is re-established, and no stresses that will not? I. adding some Cl2 II. raising the temperature at constant pressure III. decreasing the volume at constant temperature
Answer:
The answers are in the explanation
Explanation:
Based on Le Châtelier's principle, when a system in equilibrium change a condition, the system will produce a reaction in order to subtract the effect of the initial change.
For the equilibrium:
2Cl2 (g) + 2H2O (g) + heat ↔ 4HCl (g) + O2 (g)
I. Adding some Cl₂. Will produce the equilibrium shifts to the right in order to decrease the concentration of Cl₂ and produce more HCl.
II. raising the temperature at constant pressure. As the system requires heat to produce the reaction, the system will shift to the right in order to decrease the heat and produce more HCl
III. decreasing the volume at constant temperature. As the volume decreases, the pressure increases. In the left, there are 4 moles of gas and in the right there are 5. When the pressure increases the system will try to decrease the moles of gas in order to decrease the pressure. THat means the system will shift to the left in order to produce more Cl₂
Given the following chemical reaction:
N2 + 202 --> 2 NO2
How many liters of N2 are needed to react with 10 liters of Q? Explain
Answer:
1
Explanation:
one volume of nitrogen to react
Suspensions can be undersaturated.
O True
O False
Answer:
true
Explanation:
2) A balloon was inflated to a volume of 5.0 liters at a temperature of
7.0°C. It landed in an oven and was heated to 147°C. What is its new
volume?
Answer:
6.12 L
Explanation:
Given that,
Initial volume, V₁ = 5 L
Initial temperature, T₁ = 7.0°C = 343 K
Final temperature, T₂ = 147°C = 420 K
We need to find its new volume. The relation between volume and temperature is given by :
[tex]\dfrac{V_1}{T_1}=\dfrac{V_2}{T_2}\\\\V_2=\dfrac{V_1T_2}{T_1}\\\\V_2=\dfrac{5\times 420}{343}\\\\V_2=6.12\ L[/tex]
So, the new volume is 6.12 L.
What important material is absorbed by your digestive system besides water
Answer:
The monosaccharides, amino acids, bile salts, vitamins, and other nutrients are absorbed by the cells of the intestinal lining
Explanation:
Answer:
The monosaccharides, amino acids, bile salts, vitamins, and other nutrients are absorbed by the cells of the intestinal lining.
Explanation:
A sample of an unknown compound is vaporized at 130°C . The gas produced has a volume of 1280mL at a pressure of 1.00 atm and it weighs 4.03g
Assuming the gas behaves as an ideal gas under these conditions, calculate the molar mass of the compound. Round your answer to 3 significant digits.
What physical property of matter determines the earth ?
Answer:
Density is a physical property that is determined by dividing the mass of a given amount of a substance by its volume.
Explanation:
2 C.H. (g) + 190, (g) → 1200, (g) + 147,0 (8)
Answer:
please your question is not understandable
What is the scaling factor if the molar mass of
this compound, having an empirical formula of
ch2o, is 150 g/mol?
Answer:
The scaling factor is 5.
Explanation:
Hello there!
In this case, since the scaling factor is defined as the ratio of the molar mass of the molecular formula (complete) to the empirical formula (simplified), it is possible to compute it for the empirical formula of CH2O whose molar mass is 30 g/mol (12+2+16) as shown below:
[tex]sf=150/30=5[/tex]
Therefore, we can also infer that the molecular formula would be:
[tex]C_5H_1_0O_5[/tex]
Best regards!
In which way do buffalos protect themselves from predator animals such as lions
Answer: Both males and females have sharp, curved horns extending from the sides of their heads which are used to defend themselves against predators.
Explanation:
Do not abuse or misuse any piece of drawing instrument. ASAPPPP
What is another name for a mole?
O A. Rutherford's number
O B. Mendeleev's number
O C. Dalton's number
D. Avogadro's number
Answer: D Avogadro’s Number
Explanation:
Another name for a mole is Avogadro's number. option D) is correct.
What is a Mole?
A mole refers to the amount of a substance that contains as many elementary units as can be found in 12g of Carbon-12. It can also be a number of a substance /particles, such as atoms or ions. molecules or electrons. The number of particles is approximately 6.02* 10²³ in magnitude and is called Avogadro's number of particles. it can be denoted with 'mol'.
Formula for calculating mole.
n = N/Nₐ
Where,
n = number of moles of the substance (or elementary entity)
N = total number of elementary entities in the sample
Nₐ= Avogadro constant.
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would you rather eat pizza the rest of your life, or cake?
Answer:
cake
Explanation:
now here me out, no cake is specified so i can say i want a cake that has pizza on it, take off the pizza, and eat it, this goes with any other food without me having to eat the cake