Which scientist’s law about the ratios of masses of elements in a compound did John Dalton’s work on the atomic structure help to explain?
Answers
This law helped shape Dalton's work on the Law of Multiple Proportions which states that several compounds can contain the same group of elements. The ratios of the elements' masses in the compounds are always whole numbers.
Answer:
joseph proust took the edge test
Explanation:
Related Questions
When solid ammonium carbonate is heated, it decomposes to form ammonia gas, carbon dioxide gas, and water vapor, so that the solid completely disappears. Write a complete, balanced equation for this reaction.
Which value is most likely to be the pH of a salt that is formed by the reaction of a strong acid and a weak base?2.0 7.0 8.0 10.0
Cohesion is the tendency for the same type of molecules to stick together. TRUE or FALSE
Given the balanced equation representing a reaction: 2NaCl -> 2Na + Cl2 A 1170. gram sample of NaCl completely reacts, producing 460. grams of Na. What is the total mass of Cl2 produced?
Answers
Answer:
They are composed by two or more pure substances.
Explanation:
Hello,
At first, we must take into account that mixtures are such materials made up of two or mire pure substances, say elements, molecules or compounds. They are classified as homogeneous for which there is no appreciable difference upon its constituents and as heterogeneous for which the constituents are differentiable. Now, stainless steel is considered as a mixture as long as it is mainly composed by iron and carbon and some other metallic elements such as chromium. Sea water is another interesting example, since the main constituents are water and sodium chloride, nonetheless, other ions such as iodide, sulfate, magnesium (II), potassium (I), calcium (II) are also found into it. Finally, the air is a mixture due to the presence of oxygen and nitrogen as the major constituents, considering others such as carbon dioxide, methane (pollution), argon, hydrogen as traces, it means, compositions below the 1%.
Best regards.
Think of a homogeneous mixture similar to salt water. Homogeneous mixtures have a fixed, or uniform composition. This means that each part of the mixture has the same properties. Every part of the sample is identical to the next. The same thing would happen with steel and bronze, they too are uniform throughout.
Figure 11 shows the results
time taken for amylase to produce glucose (s)
Test 4
120
125
110
115
Figure 11
() Calculate the rate of amylase enzyme activity for the 10% starch solution.
Answers
Answer:
Phenolphthalein is an indicator. It is pink in alkaline solutions and turns colourless as the pH decreases.
It can be used to measure the activity of the enzyme lipase on the breakdown of lipids.
Samples of milk containing phenolphthalein were incubated with lipase at different temperatures.
The time taken for the phenolphthalein to turn colourless was recorded and used to calculate the rate of enzyme activity.
Figure 10 shows these results.
Picture
(a) (i) Explain why phenolphthalein turns colourless when lipase breaks down the lipids in milk. (2)
(ii) Describe the effect of temperature on the activity of lipase, as shown in Figure 10. (2)
(iii) Explain why the activity of lipase changes above a temperature of 40°C. (2)
(b) A student investigated the time taken for amylase to breakdown a 10% starch solution into glucose at 37°C. The student repeated the investigation five times.
Final answer:
To calculate the rate of amylase enzyme activity for the 10% starch solution, divide the time taken for amylase to produce glucose by the total time elapsed. For each test, this rate can be expressed as the number of glucose molecules produced per unit of time.
Explanation:
The rate of amylase enzyme activity for the 10% starch solution can be calculated by determining the time taken for amylase to produce glucose. In this investigation, the time taken for amylase to break down the starch solution into glucose was recorded in seconds. To find the rate, divide the amount of glucose produced (in this case, the time taken) by the total time elapsed. For example, for Test 4, the time taken was 120 seconds. The rate of amylase enzyme activity can then be expressed as 1 glucose molecule produced per 120 seconds.
Learn more about Rate of amylase enzyme activity here:
#SPJ3
Jonas Salk
Marie Curie
Carlos Finlay
Answers
(1) H2
(2) N2
(3) O2
(4) F2
Answers
Answer: (2)
Explanation:
1) is a diatomic molecule which is formed by sharing of two electrons between two hydrogen atoms.
2) is a diatomic molecule which is formed by sharing of six electrons between two nitrogen atoms.
3) is a diatomic molecule which is formed by sharing of four electrons between two oxygen atoms.
4) is a diatomic molecule which is formed by sharing of two electrons between two fluorine atoms.
two atoms share six electrons would be N2. It has five valence electrons, so it needs three more valence electrons to complete its octet.
B ratio that describes the amount of solvent or solution divided by the amount of solute
C ratio that describes the mass of solute divided by the mass of solvent
D ratio that describes the amount of solvent in a solution
2 Which contributes to the dissolution of sugar in water?
A the dissociation of an ionic compound in water
B a strong pull of water molecules on an ionic compound
C the dissociation of a polar covalent compound in water
D a strong pull of water molecules on a polar covalent compound
Answers
These are two questions and two answers.
Question 1: Which best defines concentration?
Answer: option A, ratio that describes the amount of solute divided by the amount of solvent or solution
Explanation:
There are many different measures of concentration: percent, molarity, molality, mole fraction are some examples.
All of them express the ratio of solute to solvent or solution, in different kind of units, may be mass, number of moles, or volume.
Molarity is number of moles of solute per liter of solution. Molality is number of moles of solute per kg of solvent.
So, as you see it is always a ratio of the amound of solute, but it is not a fixed unit.
Question 2. Which contributes to the dissolution of sugar in water?
Answer: option D, a strong pull of water molecules on a polar covalent compound.
Explanation:
Sugar is not a ionic compound so it does not dissociate.
Sugar is a molecule, so it remains as such in solution.
Sugar is polar, so it can be dissolved in water that is a polar solvent (like dissolve like, is the rule).
The dissolution is explained by the fact that the pull exerted by the molecultes of solvent on the molecules of solute, is greater than the pull that the molecules of solute extert among themselves.
That permits the molecules of solvent surround the molecules of solute and get them appart of the solid substance to form the aqueous solution.
Concentration is the ratio that describes the amount of solute divided by the amount of solvent or solution; option A
The dissociation of sugar in water is due to a strong pull of water molecules on a polar covalent compound; option D
What is concentration of a solution?
Concentration of a solution is the amount of solute present in a given volume of solution.
Thus, concentration is the ratio that describes the amount of solute divided by the amount of solvent or solution.
The dissolution of sugar in water forms a sugar solution.
Sugar is a polar covalent molecule. The dissociation of sugar in water is due to a strong pull of water molecules on a polar covalent compound.
Learn more about polar compounds at: brainly.com/question/1433127
#SPJ5
Answers
Answer:
Phosphorus
Explanation: