A sample of river wayer contains 125mg per dm^3 of dissolved soilds. Calculate the mass of dissolved soilds in grams in 250 cm^3 of this sample of river water. Giver your answer to 2 significant figures (4 marks)
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Answers
Answer is in g convert mg into g = 125/1000= 0.125g
This means there is 0.125g of solids in 0.25dm3
Need to know how much is in 1dm3
0.25dm3 is 1/4 of 1dm3
0.125/4 = 0.03125
0.031g (2S.F)
The mass of a substance is the product of its density and volume. Thus, the mass of the dissolved solids with a density of 125 mg/dm³ with a volume of 250 cm³ is 31.25 mg.
What is density?Density of a substance is the measure of its mass per unit volume. Thus it describes how much denser the substance is in a given volume. Mathematically it is the ratio of mass to the volume.
Density of a substance depends on the mass, volume, bond type, temperature and pressure. The ratio of density of a substance with the density of water is called its specific gravity.
It is given that the density of the dissolved solids is 125 mg/dm³ and the volume is 250 cm³ or 0.25 dm³. Thus the mass can be calculated as follows:
density = mass/volume
mass = density × volume
= 0.25 dm³ × 125 mg/dm³
= 31.25 mg
Hence, the mass of the dissolved solids in the river wayer is 31.25 M=mg.
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Related Questions
Base A dissociates 25% in water. Base B dissociates 50%. Base C dissociates
75%. Which base is the WEAKEST conductor of electricity?
Answers
Answer:Base A is the weakest conductor electricity
Explanation:
Dissociation is a factor that affects electrical conductivity. The greater the percentage of dissociation for bases the stronger the conductivity of electricity.
Given that
Base A dissociates 25% in water
Base B dissociates 50%.
Base C dissociates 75%
We can conclude that Base A is the weakest conductor oelectricity since it has the lowest percentage of dissociation.
Which of the following is a property of carbon atoms?
They are chemically inert.
They have six valence electrons.
They readily give up two electrons
They are found in all living things.
Answers
They are found in all living things. Hence, option D is correct.
What is an atom?An atom is any particle of matter which contains at least one proton.
Carbon is stored in plants and trees. Plants take carbon dioxide from the atmosphere to make the building blocks of food during photosynthesis. Carbon is stored in the hydrosphere and dissolved in ocean water and lakes. Carbon is used by several organisms to produce shells.
Hence, option D is correct.
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Can animals and plants adapt to climate changes?
Answers
Answer:
Yes but will take a very very long time for them to adapt most will die but as gemeration passes they will get used to it
What percentage of a substance remains after 7 half-lives have passed?
A. 0.39
B. 2.5
C. 1.25
D. 0.78
Answers
Answer:
Not really sure, buts its either B or C.
Convert 22 grams of copper Il chloride (Cucl2) to moles.
with work please
Answers
https://youtu.be/MT5tKijKZwQ
What would make oppositely charged objects attract each other more?
increasing the positive charge of the positively charged object and increasing the negative charge of the negatively
charged object
decreasing the positive charge of the positively charged object and decreasing the negative charge of the negatively
charged object
increasing the distance between the positively charged object and the negatively charged object
maintaining the distance between the positively charged object and the negatively charged object
Answers
Answer: increasing the positive charge of the positively charged object and increasing the negative charge of the negatively charged object.
Explanation:
edge
Answer:
Your answer is A.
Explanation:
A Chemist reacted magnesium and aluminum oxide. A reaction takes place. Explain why
Answers
Explanation:
when Magnesium is reacted with Aluminum oxide, Aluminum being a less reactive metal than magnesium, is replaced by magnesium
Al2O3 + 3Mg - 3MgO + 2Al
hence reaction takes place
A loose pile of rocks and soil travels in a single large mass the mass moves a short distance downhill which mass movement does this describe
A. Creep
B. Erosion
C. Landslide
D. Slump
Answers
Calculate how many grams of sodium chloride we would need to make a solution with the same molarity of seawater, which is about 0.598 M.
Answers
Answer:
34.92 grams NaCl (in 1 L of solution)
Explanation:
The chemical formula of sodium chloride is NaCl. From the formula, we can calculate the molar mass of NaCl:
MM(NaCl)= MM(Na) + MM(Cl) = 23 g/mol + 35.4 g/mol = 58.4 g/mol
A solution of NaCl with a molarity of 0.598 M has 0.598 moles of NaCl per liter of solution. So, we multiply the moles by the molar mass of NaCl to calculate the mass we need:
mass of NaCl = 0.598 mol x 58.4 g/mol = 34.92 g NaCl
Therefore, we need 34.92 grams of NaCl to prepare 1 liter of a solution with a molarity of 0.598 M.
24.
What is the molar mass of CO2?
Answers
Answer:
The molecular mass of carbon dioxide is 44.01amu
That big lorry hit the new car.change to passive voice
Answers
Which is the correct chemical formula for Pentacarbon Tetraphosphide
Answers
Answer:
C5P4
Explanation:
the answer is C5P4 because penta is 5 and tetra is 4
2C2H2 + 5O2 → 4CO2 + 2H2O
Which of the following statements would be correct if one mole of C2H2 was used in this reaction? (5 points)
a
One mole of oxygen was used in this reaction.
b
Five moles of oxygen were used in this reaction.
c
Four moles of carbon dioxide were produced from this reaction.
d
Two moles of carbon dioxide were produced from this reaction.
Answers
Answer:
d. Two moles of carbon dioxide were produced from this reaction
Explanation:
The given chemical reaction can be written as follows;
2C₂H₂ + 5O₂ → 4CO₂ + 2H₂O
From the above chemical reaction, we have;
Two moles of C₂H₂ reacts with five moles of O₂ to produce four moles of CO₂ and two moles of H₂O
We have;
One mole of C₂H₂ will react with two and half moles of O₂ to produce two moles of CO₂ and one mole of H₂O
Therefore, in the above reaction, when one mole of C₂H₂ is used, two moles of CO₂ will be produced.
What is the number of moles in a sample of gas that has a volume of 3.5 L, a
pressure of 200 kPa, and a temperature of 300 K?
Answers
Explanation:
[tex]PV = nRT \\ (200000 \times 3.5 \times {10}^{ - 6} ) = n \times 8.314 \times 300 \\ n = \frac{0.07}{2494.2 } \\ n = 2.81 \times {10}^{ - 5} [/tex]
[tex] \small{ \star{ \underline{ \blue{ becker}}}}[/tex]
Clouds are made up of tiny droplets of water. Which two spheres are clouds a
part of?
A. Biosphere
B. Geosphere
C. Hydrosphere
D. Atmosphere
Answers
Select the correct mass for each of the samples described below.
3.01 × 1023 molecules H2O
Answers
Answer:
9.00 g H2O
Explanation:
Convert molecules to grams using stoichiometry
(3.01 * 10^23 molecules) * (1 mole H2O / 6.022 * 10^23 molecules) * (18.01 g / 1 mole H2O) = 9.00 g H2O
Answer:
answer in picture
Explanation:
Al+3 and I-
what is the chemical formula and what is the name of the compound
Answers
Answer:
AlI3 is the chemical formula and the name of compound is Aluminium iodide.
If two half lives have passed since a scientist collected a 1.00- gram sample of a U-235, how much U-235 is left now?
answers for most finals chem test questions (10th)
Answers
Answer:
one quarter of the original amount, so 0.25 g
Explanation:
Answer:
C
Explanation:
Answer is C
Zeke is attempting to react a piece of magnesium metal with sulfuric acid. The sulfuric acid is a 5M solution. What could Zeke do
to slow down the rate at which the magnesium will react with the acid?
A)
increase the temperature
B)
add a 10M sulfuric acid solution
9)
add water to the acid to decrease its molarity
D)
add more of the 5M sulfuric acid to the reaction
Answers
Answer:
c)
Explanation:
add water to the acid to decrease its molarity
A student finds that the water's temperature went from 18oC to 38oC. Calculate how many calories are in the peanut.
Answers
Answer:
567 calories.
Explanation:
There 567 calories in 100 grams of peanut. In 100 grams of peanut, 49 gram is the fat, 26 grams of protein, 16 grams of carbohydrates, Sodium is 18 mg, Potassium is 705 mg. Calcium is present in peanut about 9%, Iron is 25% , Vitamin B-6 is 15% and Magnesium is 42% of their total weight. Oil content is high in the Peanut so this is the reason for high calories in peanut. It is a good source of proteins and potassium.
Mendel crossed tall pea plants with short pea plants. the offspring were all tall plants.
1. Which allele is recessive?
2. Which allele is dominant?

please hurry

Answers
Answer:
1. Allele for shortness (t)
2. Allele for tallness (T)
Explanation:
Gregor Mendel performed numerous experiments using pea plants (Pisium sativum). He tested the height traits of pea plants by crossing tall pea plants (TT) and short pea plants (tt) to obtain offsprings that were all tall (Tt) in the first filial generation (F1).
This is possible because the allele for tallness is DOMINANT while the allele for shortness is RECESSIVE. This means that tallness allele (T) will mask the phenotypic expression of shortness allele (t) when in an heterozygous state (Tt) as in the F1 generation.
Structures and Forces - What is force and external forces.
Question 1) Jacob and Ravleen are moving furniture. They need to move the filing cabinet over 6 feet and it is very heavy. Jacob wants to apply force and push it by putting his hands on point A because he thinks it would be easier to move it from the top as there is less weight on the top. Ravleen says it's better to push at point B because the center of gravity is lower. Which person is correct and EXPLAIN why and what may happen if it is pushed in the wrong spot.
Answers
Answer:
The restoring force that prevents the furniture from tipping over when pushing the furniture towards the right, F= W × D
Where;
W = The weight of the furniture
D = The horizontal distance from the center of gravity of the furniture, CG and the to the lower right corner of the furniture
Given that A > D, for the furniture to tip over when pushing above the CG, we have;
F1 × A ≤ W × D
∴ F1 << W or for a force much smaller than W, the weight of the furniture applied above the center of gravity, the furniture will tip over
However when the force F2 is applied, where C < D, we have for no tipping over;
F2 × C ≤ W × D, therefore, given that C < D, when a force much higher than the weight, W, is applied at F2, the furniture will remain upright
Therefore, it is better push at a point lower than or equal to the center of gravity, whereby the point B is lower than the center of gravity, it is better to push at point B, Ravleen is correct and it is better to push at point B because the center of gravity is lower
If the furniture is pushed at the wrong spot it may tip over
Please see attached drawing
Explanation:
URGENT!!!
Which statement explains why an increase in molality increases the boiling point of a solution? The addition of solute decreases the solvent’s vapor pressure. A higher temperature must then be applied to overcome the change. The addition of solute increases the solvent’s vapor pressure. A higher temperature must then be applied to overcome the change. The addition of solute increases the solvent’s ability to boil. The solute’s molecules repel the solvent’s molecules, giving them higher binding energy and hence the need for higher temperature.
Answers
Answer:
the addition to solute decreases the solvent's vapor pressure. a temperature must then be applied to overcome the change
Explanation:
Answer:
long story short: A
Explanation:
A gas diffuses 1/6 times faster than hydrogen gas (H2).
What is the molar mass of the gas? (5 points)
a
59.95 g/mol
b
66.54 g/mol
c
68.68 g/mol
d
72.58 g/mol
Answers
Answer:
72.58 g/mol
Explanation:
mark me brainless if I am ✅
The relationship between the rate of diffusion and the molar mass is given by Graham's law. A gas diffusing 1/6 times faster than hydrogen will have a molar mass of 72.58 g/mol. Thus, option d is correct.
What is Graham's law?Graham's law states the inverse relationship between the rate of diffusion and the square root of the molar mass of the gas. It is given as,
Rate = 1 ÷ √M
The molar mass of the gas that diffuses 1/6 times faster than hydrogen is calculated as,
R₁ ÷ R₂ = √ (M₂ ÷ M₁)
Here,
The molar mass of hydrogen = M₁
The molar mass of unknown gas = M₂
Rate of diffusion of hydrogen gas = R₁
Rate of diffusion of unknown gas = R₂ = 1 / 6 R₁
Substituting values:
R₁ ÷ 1/6 R₁ = √M₂ ÷ 2
6 × 1.414
= 8.485
= 84.85 g/mol ≈ 72.58 g/mol
Therefore, option d. 72.58 g/mol is the molar mass of unkown gas.
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URGENT: Identify the subatomic particles that determine the atomic number of an element.
Answers
Answer:
the number of protons determines the atomic number
Explanation:
Ex. Aluminum has 13 protons, so it's atomic number is 13
hope this helps :)
What is catalyst? Write its types.
Answers
Answer:
A catalyst is a chemical substance that alters the rate of chemical reaction not consumed by the reaction. Hence, a catalyst can be recovered chen unchanged at the ends of chemical reaction. Catalyst can be divided into two typ the basis whether it speeds up or slowdowns the rate of chemical reaction. The positive catalyst and negative catalyst.
Answer:
A catalyst is a chemical substance thatalters therate of chemical reactions not consumed by the reactions.
What is the role of a consumer in the flow of energy through a food chain?
Answers
Answer:
The role of consumers in an ecosystem is to obtain energy by feeding on other organisms and sometimes transfer energy to other consumers. Changes that affect consumers can impact other organisms within the ecosystem.
Explanation:
Hope this helped Mark BRAINLIEST!!!!
Consumers are organisms that obtain energy by eating other organisms. Consumers may consume either producers or other consumers. Consumers include animals.
What is food chain ?A food chain is a network of links in a food web that begins with producer organisms and ends with an apex predator, detritivore, or decomposer species.
A food chain also demonstrates how organisms are related to one another through the food they consume. Each trophic level is represented by a different level of a food chain.
Producers can produce their own food and energy, but consumers are not the same. Consumers are living things that must hunt, gather, and eat their food.
Thus, Consumers must eat in order to gain energy, or they will perish. Omnivores, carnivores, herbivores, and decomposers are the four types of consumers.
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Need help on this question asap pleasee
Answers
Answer:
9.0 moles of CaO
Explanation:
We have the reaction equation as follows;
Fe2O3 + Ca3(PO4)2 -------> 2FePO4 + 3CaO
Now we know from the equation that;
1 mole of iron III oxide yields 3 moles of CaO
Therefore;
3 moles of iron III oxide yields 3 * 3/1
= 9.0 moles of CaO
How many grams are there in 7.40 moles of AgNO3?
Answers
Answer:
1257.03 grams
Explanation:
mass=mole*molar mass
mass=7.4*169.87= 1257.03
Using the balanced equation for the next few questions: 4 Fe(s) + 30 (9) - 2Fe2O3(s)
How many moles of Iron (11) Oxide would be produced by complete reaction of 0.15
moles of iron? (Be sure to show your work including the mole ratio you used)
Answers
Answer:
0.075 moles of iron oxide would be produced by complete reaction of 0.15 moles of iron.
Explanation:
The balanced reaction is:
4 Fe + 3 O₂ → 2 Fe₂O₃
By reaction stoichiometry (that is, the relationship between the amount of reagents and products in a chemical reaction), the following amounts of moles of each compound participate in the reaction:
Fe: 4 molesO₂: 3 molesFe₂O₃: 2 molesYou can apply the following rule of three: if by stoichiometry 4 moles of Fe produce 2 moles of Fe₂O₃, 0.15 moles of Fe produce how many moles of Fe₂O₃?
[tex]moles of Fe_{2} O_{3} =\frac{0.15 moles of Fe*2 moles of Fe_{2} O_{3} }{4 moles of Fe}[/tex]
moles of Fe₂O₃= 0.075
0.075 moles of iron oxide would be produced by complete reaction of 0.15 moles of iron.