Answer:
Water is life, as the saying goes. We rely on water for our food, our health, our livelihoods, and for fun and leisure. But water can also take away life, and the absence of water can be even worse. Currently, 700 million people live in water-stressed areas. By 2025, this number is expected to grow 1.8 billion — about 25% of the world population.
As Number 6 on the UN’s Sustainable Development Goals, “Clean Water and Sanitation For All” is currently struggling. The UN suggests that, if we want to meet this goal by the deadline of 2030, we’ll need to double our current rate of progress to ensure that there’s universal access to safe and affordable drinking water, adequate sanitation and hygiene resources, improved water quality, and restored water-related ecosystems. Here are 5 ways that water affects our lives — and what we’re doing to help make them happen.
Explanation:
Many of the towns we live in were built near water sources. Oceans, rivers, streams and lakes make up some of our geographical boundaries. They also allow for water transportation and commerce and provide food and other resources.
a compound has an empirical formula of C7H12O and a formula mass of 224g. what is the compound molecular formula
Explanation:
fyuvgddykhadkxdiyflhdfhyddkgd
How many gram are in 4.5 moles of Li2O
Answer:
134.5 grams
Explanation:
There are 134.5 grams in 4.5 moles of Li2O (lithium oxide).
BRAINLIEST PLZZZZZ
Mole measure the number of elementary entities of a given substance that are present in a given sample. Therefore, 135g are in 4.5 moles of Li[tex]_2[/tex]O.
What is mole?The SI unit of amount of substance in chemistry is mole. The mole is used to measure the quantity of amount of substance. we know one mole of any element contains 6.022×10²³ atoms which is also called Avogadro number. Mole is inversely proportional to molar mass of given substance. Mole is directly proportional to given number of atoms present in that substance.
Mathematically, molar mass and mole can be related as
mole of Li[tex]_2[/tex]O =given mass of Li[tex]_2[/tex]O÷ Molar mass of Li[tex]_2[/tex]O
Molar mass of Li[tex]_2[/tex]O=30 g/mol
mole of Li[tex]_2[/tex]O=4.5 moles
Substituting the values
4.5 moles =mass of Li[tex]_2[/tex]O÷ 30 g/mol
mass of Li[tex]_2[/tex]O = 135g
Therefore, 135g are in 4.5 moles of Li[tex]_2[/tex]O.
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14.) What volume of 0.504 M barium nitrate solution is needed to prepare 218. mL of a solution that is 0.244 M in nitrate ion
Answer:
105.5 mL
Explanation:
To solve this problem we can use the following equation:
C₁V₁=C₂V₂Where:
C₁ = 0.504 MV₁ = ?C₂ = 0.244 MV₂ = 218 mLWe input the data:
0.504 M * V₁ = 0.244 M * 218 mLAnd solve for V₁:
V₁ = 105.5 mLThe volume of 0.504 M barium nitrate solution is needed to prepare the solution is 52.77 mL
We'll begin by calculating the molarity of the diluted barium nitrate solution. This can be obtained as follow:
Ba(NO₃)₂(aq) —> Ba²⁺(aq) + 2NO₃¯(aq)
From the balanced equation above,
2 mole of NO₃¯ is present in 1 mole of Ba(NO₃)₂
Therefore,
0.244 M NO₃¯ will be present in = 0.244 / 2 = 0.122 M Ba(NO₃)₂
Finally, we shall determine the volume of 0.504 M barium nitrate needed to prepare the solution
Molarity of stock solution (M₁) = 0.504 M
Volume of diluted solution (V₂) = 218 mL
Molarity of diluted solution (M₂) = 0.122 M
Volume of stock solution needed (V₁) =?M₁V₁ = M₂V₂
0.504 × V₁ = 0.122 × 218
0.504 × V₁ = 26.596
Divide both side by 0.504
V₁ = 26.596 / 0.504
V₁ = 52.77 mLTherefore, the volume of 0.504 M barium nitrate needed to prepare the solution is 52.77 mL
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The answer to the problem: 3.6 x 4.639 + 5.831 = _____, written to the correct number of significant digits is:
Answer:
3.6 x 4.639 + 5.831 = 2000
Explanation:
In this problem, we need to find the value of 3.6 x 4.639 + 5.831.
Here, 3.6 has 2, 4.639 and 5.831 has 4 significant figures.
We can use BODMAS RULE to find it as follows :
3.6 x 4.639 + 5.831 = (3.6 x 4.639) + 5.831
= 2325.96 + 5.831
in significant gigure,
= 2300 + 5.831
= 2305.831
In one significant figure,
= 2000
Hence, the answer of the problem is 2000.
Which type of solid can be described by the unknown solid if it has the properties listed in the table below?
Appearance
Brittle white crystals
Melting Temperature
3700°C
Soluble in Weter
yrs
Conductive
no
Conducive la Water
yes
A. molecular
B. covalent
C. metallic
D. ionic
Answer:
Ionic
Explanation:
Name the following compound: S₂O₇
Answer:
disulfur heptoxide
Explanation:
Refer to the radioisotope colbalt-60, which has a half life of 5.3 years. An initial sample of colbalt-60 has an activity of 12,400cpm. How much time has passed if the activity of the sample has dropped to 775cpm
Answer:
21.2 years
Explanation:
If half life is 5.3 years, that means activity will be 50% every 5.3 years.
12,400 x 50% = 6,200
6,200 x 50% = 3,100
3,100 x 50% = 1,550
1,550 x 50% = 775
4 half lives, so 4 half lives x 5.3 years/half life = 21.2 years
Adding ammonia (NH3) to water makes NH4. This will cause the pH of the solution to:______.
Answer:
pH increases
Explanation:
The ammonia, NH₃, reacts with water, H₂O, as follows:
NH₃ + H₂O → NH₄⁺ + OH⁻
That means when NH₃ is added to water, some OH⁻ is produced. As [H⁺] is inversely proportional to [OH⁻], the increase of OH⁻ causes the decrease og H⁺. And when H⁺ decreases,
pH increases
Scan the list below for explanations of how
scientists applied knowledge of gecko feet to
produce an adhesive. Click each way that you
included in your response.
The researchers created an adhesive made
from carbon nanotubes.
The adhesive is made up of two different
layers.
The lower layer is made up of vertically
aligned nanotubes.
The upper layer is made up of curly, spaghetti
like, nanotubes.
Answer:
its the last 3...
Explanation:
the adhesive is made up of 2 different layers.
the lower layer is made up of vertically aligned nanotubes.
the upper layer is made up of curly, spaghetti like, nanotubes.
How many milliliters of 0.128 M nitric acid are required to neutralize 11.1 mL of 0.184 M sodium hydroxide? Answer with the correct number of significant digits.
Answer:
I think 7.72 mL
11.1/184 × 128/184=7.72
Question 3 Multiple Choice Worth 1 points)
(01.06 MC)
The contents of two beakers are described in the table.
Contents of Beakers
Beaker
Contents
Final Substance Formed
х
sugar, water sugar not visible in water
Y
sand, water sand settled at the bottom of the beaker
Which statement is true about the final substances formed in the beakers?
The final substances in both the beakers are mixtures.
The final substances in both the beakers are pure substances.
The final substance in Beaker X is a pure substance and in Beaker Y is a mixture.
The final substance in Beaker X is a mixture and in Beaker Y is a pure substance.
Answer:
the asnwer is B
Explanation:
The contents of two beakers X sugar, water sugar not visible in water Y sand, water sand settled at the bottom of the beaker final substance in Beaker X is a pure substance and in Beaker Y is a mixture. option C is correct.
What is mixture and pure substance?A mixture is a material made up of of two or more substances and this type of material can be compounds or chemical elements or mixture of liquids, solids, or gases can be produced.
A pure substance is the homogeneous mixture of two of more components is called the pure substance an if components are 2, 3, or 4 in number then the solution will be binary , tri-nary or quaternary.
Therefore, contents of two beakers X sugar, water sugar not visible in water Y sand, water sand settled at the bottom of the beaker final substance in Beaker X is a pure substance and in Beaker Y is a mixture. option C is correct.
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throwing a snowball during a snowball fight is most like an example of r. weather s. erosion t. deposition. v. acumulation
Answer:
V. accumulation
Explanation:
because the snow had to accumulate enough in order to make a snowball
Throwing a snowball during a snowball fight is most like an example of accumulation.
Accumulation refers to the gradual gathering of matter. This occurs overtime and may be as a result of events such as erosion. In a snowball fight, people throw snowballs at each other and the snowball eventually accumulates during the game.
Hence, throwing a snowball during a snowball fight is most like an example of accumulation.
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A scientist completes a thermal decomposition reaction. 12.25g of calcium carbonate, CaCO3, is heated
and forms calcium oxide, Cao, and carbon dioxide, CO2.
a. Write a balanced chemical equation to demonstrate this reaction. Include state symbols.
b. Calculate the number of moles of calcium carbonate that is thermally decomposed in this
reaction.
Ok
Moles of calcium carbonate : 0.1225
Further explanationA reaction coefficient is a number in the chemical formula of a substance involved in the reaction equation. The reaction coefficient is useful for equalizing reagents and products.
Reaction
CaCO₃(s) → CaO(s) + CO₂(g)
mass of CaCO₃ : 12.25 g
mol CaCO₃(MW=100 g/mol) :
[tex]\tt mol=\dfrac{mass}{MW}\\\\mol=\dfrac{12.25}{100}\\\\mol=0.1225[/tex]
If the compound below is oxidized, the resulting product is:______CH3--CH2--CH2--CO--Ha) methane and propane b) butanal c) butanoic acid d) butane
Answer:
Butanal
Explanation:
alkanes are not oxidized
Carboxylic acids cannot be oxidized
Alkanals can be oxidized
What will happen If you heat a liquid to high temperatures?
Answer:
The evaporation will take place - then once the liquid has reached its boiling point it will start to change into a gas.
HELPPPPP WILL MARK BRAINLIEST
Which are advantages of reflecting telescopes? Check all that apply.
A)There is no rainbow-like halo around the image.
B)Reflecting telescopes can be made very large.
C)Reflecting telescopes use only lenses, not mirrors.
D)Only the reflecting side of the primary mirror needs to be perfectly shaped and smooth.
E)The eyepiece creates an image for the observer.
Answer: a.b.d
Explanation:
Answer:
A)There is no rainbow-like halo around the image. Yes
B)Reflecting telescopes can be made very large. Yes
C)Reflecting telescopes use only lenses, not mirrors. No
D)Only the reflecting side of the primary mirror needs to be perfectly shaped and smooth. Yes
E)The eyepiece creates an image for the observer. No
23. The compound which contains both ionic and covalent compound is
a)CH4
b) H2
c)KCN
d)KCL
Calcium carbonate is another example of a compound with both ionic and covalent bonds. Here calcium acts as the cation, with the carbonate species as the anion. These species share an ionic bond, while the carbon and oxygen atoms in carbonate are covalently bonded.
Answer:
D and C
Explanation:
KCl
because potassium ion ( K† ) is ionic and Chloride ion ( Cl- ) is covalent.
also KCN can be an alternative answer because the potassium ion ( K† ) is ionic and Cyanide ion ( CN- ) is covalent.
Write the names of stages in the life cycle of butterfly
Answer:
There are four stages in the metamorphosis of butterflies and moths: egg, larva, pupa, and adult.
Hope this helps :)
How much does 0.0273 moles of Na2O weigh
Answer:
1.69 g Na₂O
General Formulas and Concepts:
Chemistry - Atomic Structure
Reading a Periodic TableUsing Dimensional AnalysisExplanation:
Step 1: Define
0.0273 mol Na₂O
Step 2: Identify Conversions
Molar Mass of Na - 22.99 g/mol
Molar Mass of O - 16.00 g/mol
Molar Mass of Na₂O - 2(22.99) + 16.00 = 61.98 g/mol
Step 3: Convert
[tex]0.0273 \ mol \ Na_2O(\frac{61.98 \ g \ Na_2O}{1 \ mol \ Na_2O} )[/tex] = 1.69205 g Na₂O
Step 4: Check
We are given 3 sig figs. Follow sig fig rules and round.
1.69205 g Na₂O ≈ 1.69 g Na₂O
Based on the octet rule, nitrogen most likely forms a __ion.
a) N3+
b) N3-
d) N2+
c) N2
Answer:
b) N3-
Explanation:
The octet rule stipulates that a chemical specie is stable if it has eight electrons in its outermost shell.
Nitrogen belongs to group 15. This means that it has five electrons in its outermost shell. The formation N3- means that it accepted three electrons.
This brings the total number of outermost electrons to eight in accordance with the octet rule.
Pretty ez im just dum, extra points!!!!!!!
A scientist is trying to classify an unknown element. He finds that the element is like a metal because it is shiny, but also like a nonmetal because it is not malleable. He also finds that the conductivity of the element is in between that of a metal and a nonmetal.
How should this element be classified?
A. as a metalloid
B. as a compound
C. as a metal
D. as a nonmetal
Answer:
As a compound maybe, I'm not quite sure.
sorry and good luck.
Answer:
Pretty late, but the answer is as a metalloid.
What is the weight of a rock that has a mass of 5.0 kg ?
Answer:
49 Newtons
Explanation:
The weight of the rock is the product of it's mad and the acceleration due to the earth's gravity(which is 9.8 meters per squared second)
So 5.0kg times 9.8 equals 49 Newtons.
g cr2o3 molar mass compound containing chromium and silicon contains 73.52 mass percent chromium. Determine its empirical formula.
a.liver e.mouth i.stomach
b.colon f.pancreas
j.large intestine c.gallbladder
g.tongue k.villi d.esophagus
h.peristalsis l.teeth
_8. stores a substance called bile, which physically breaks down fat droplets
_9. Digestion begins when salivary gland secretions enter this
_10. Minute projection extending from the walls of the small intestine and involved in absorbing products of digestion
_11. used to cut, tear, and grind food; adult has 32
_12. when you swallow food, muscular movements carry the food along this structure
to the stomach
13. this organ absorbs excess water form undigested food prior to its release from
the body as a solid waste
_14. Muscular movement involving the walls of the digestive tract that serve to mix materials and move them along the tract
15. it pushes food to the back of the mouth prior to swallowing
_16. this organ produces bile and detoxifies a variety of substances
_17. produces digestive juices that are released into the small intestine
_18. another name for the large intestine
19. functions include mixing food and serving as a reservoir prior to the food being passed on to the small intestine
Answer:
8. c
9. e
10. k
11. L
12. d
13. j
14. h
15. g
16. a
17. F
18. b
19. i
Explanation:
The gallbladder stores a substance called bile, which physically breaks down fat droplets, hence the correct options are 8. C, 9. E, 10. K, 11. L, 12. D, 13. J, 14. H, 15. G, 16. A, 17. F, 18. B, 19. I.
What are the components of the digestive system?Digestion begins when salivary gland secretions enter the mouth. Teeth used to cut, tear, and grind food; adult has 32.
Villi are a minute projection extending from the walls of the small intestine and involved in absorbing products of digestion.
When you swallow food, muscular movements carry the food along the esophagus to the stomach. The large intestine absorbs excess water from undigested food prior to its release from the body as a solid waste.
Muscular movement known as peristalsis involving the walls of the digestive tract that serve to mix materials and move them along the tract.
Therefore, the correct options are 8. C, 9. E, 10. K, 11. L, 12. D, 13. J, 14. H, 15. G, 16. A, 17. F, 18. B, 19. I.
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Read the given list of organisms.
rhinoceros, zebra, tortoise, rabbit, horse
What best describes the role of these five organisms in a food web? (3 points)
a
Carnivores, as they all obtain food from other animals
b
Herbivores, as they all obtain food from producers
c
Consumers, as they all eat either plants or meat
d
Consumers, as they all make their own food
Answer:
this would be c consumers as they all eat plants and/or meat
Explanation:
Answer:
(B) Herbivores.
Explanation:
Producers are plants and herbivores eat plants, and not meat, nor other animals, nor make their own food. I hope this helps good luck.
which are potential sources of error in the experiment?
Different substances
different temperatures
different enviorments
different soil
different amounts of water
2) Consider the reaction of 1-bromopropane with a solution of sodium ethanoate to form
an ester
a) Give an equation for the reaction and name the ester formed.
It is observed that when the reaction is done in solution at a high pH, another organic
product of nucleophilic substitution forms at the same time as the ester. What is the other
organic product, and will it be formed in larger or smaller amounts than the ester?
(6 marks)
Answer:
(a). CH3CH2CH2Br + CH3COONa ===> CH3COOCH2CH2CH3 + NaBr
-propylethanoate or ethylpropanoate
Another organic product is CH3COOH ( ethanoic acid ).
It will be in smaller amounts than the ether
37. Using the reaction of nitrogen gas and hydrogen gas to make ammonia gas
(NH3), if you have 7 L of nitrogen, and all the hydrogen you need, how many
liters of ammonia gas can you make?
You can make 14 L of Ammonia
Further explanationAvogadro's hypothesis:
In the same T,P and V, the gas contains the same number of molecules
So the ratio of gas volume will be equal to the ratio of gas moles
[tex]\tt \dfrac{V_1}{n_1}=\dfrac{V_2}{n_2}[/tex]
Reaction
N₂+3H₂⇒2NH₃
Volume of Nitrogen-N₂ : V₁=7 L
From the equation above, mol ratio of N₂ : NH₃ =1 : 2, so volume of NH₃ :
[tex]\tt \dfrac{7}{1}=\dfrac{V_2}{2}\\\\V_2=\boxed{\bold{14~L}}[/tex]
molecular weight of the NH3
Answer:
NH₃ = 17.03 g/mol
Explanation:
Molecular weight is calculated by adding the atomic mases of all the atoms present in a molecule.
Like in case ammonia three hydrogen atoms and one nitrogen atom are present.
1 H = 1.01 g/mol
1 N = 14 g/mol
NH₃ = 14 + (1.01×3)
NH₃ = 17.03 g/mol
How many protons are in an element with an atomic number of 8 anda mass number of 18?
3
8
10
18
Answer: 8
Explanation:
The atomic number of an element refers to the number of protons that it has in its nucleus. Carbon for instance has an atomic number of 6 because there are 6 protons in its nucleus.
This atomic number will also tell you the number of electrons the element (in its neutral state) has because protons and electrons are the same number. The reason the mass number is 18 in this scenario is that the element has 10 neutrons in its nucleus.