Answer:
Water, H2O, is a pure substance, a compound made of hydrogen and oxygen. Although water is the most abundant substance on earth, it is rarely found naturally in its pure form. Most of the time, pure water has to be created. Pure water is called distilled water or deionized water.
A sample of brass weighing 1.203g was analyzed. The zinc in the alloy was reacted with 35.123g of HCl in excess, according to the balanced equation:
Zn (s) + 2HCl(aq) - > H2(g) + ZnCl2 (aq)
After all the zinc reacted, the mass of the remaining solution weighed 36.309g
What was the mass of H2 produced?
What mass of Zn reacted?
What was the percentage of Zn (by mass) in the alloy?
The number of moles of reactants and products can be used to obtain the mass of products formed. The results obtained are as follows;
The mass of hydrogen produced is 0.0174 gramsThe mass of zinc produced is 0.5688 gramsThe percentage by mass of zinc in the brass alloy is 47.3 %The question says that HCl was in excess. It means that after the reaction, we will have unreacted HCl(aq) and ZnCl2(aq) in the remaining solution.
Hence;
Mass of ZnCl2(aq) formed = 36.309g - 35.123g = 1.186g
Number of moles ZnCl2(aq) formed = [tex]\frac{mass of ZnCl2(aq) formed}{molar mass of ZnCl2}[/tex]
[tex]\frac{1.186g}{136.286 g/mol}[/tex] = 0.0087 moles
From the reaction equation;
[tex]Zn (s) + 2HCl(aq) - > H2(g) + ZnCl2 (aq)[/tex]
To obtain the amount of Zn reacted
1 mole of Zn yields 1 mole of ZnCl2
x moles of Zn yields 0.0087 moles of ZnCl2
x = 0.0087 moles of Zn
a) 1 mole of Zn yields 1 mole of H2
0.0087 moles of Zn yields 0.0087 moles of H2
Mass of H2 = 0.0087 moles of H2 * 2 g/mol = 0.0174 grams
b)
Mass of Zn reacted = 0.0087 moles of Zn * 65.38 grams/mole = 0.5688 grams
c)
Percentage of Zn in the alloy = 0.5688 grams/1.203g * 100 = 47.3 %
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Vapor pressure of any liquid _______. A. increases with increases in temperature B. increases with decreases in temperature C. is not affected by changes in temperature D. increases with increases in volume of the liquid E. None of the Above
Answer:
increase with increases in temperature
Explanation:
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What makes an atom radioactive?
Answer:
The unstable nucleus of radioactive atoms emit radiation.
Explanation:
When the atoms of an element have extra neutrons or protons it creates extra energy in the nucleus and causes the atom to become unbalanced and unstable, or radioactive.
(https://www.epa.gov/radtown/radtown-radioactive-atom-activity-4-atomic-stability)
Answer:
When the atoms of an element have extra neutrons or protons it creates extra energy in the nucleus and causes the atom to become unbalanced or unstable. Whether radioactive elements can become stable and if so, how. The unstable nucleus of radioactive atoms emit radiation. ... This process is called radioactive decay.
Explanation:
will mark brainliest if correct
Which methods separate a mixture according to the size of the particles?
a
filtration and chromatography
b
distillation and chromatography
c
filtration and evaporation
d
distillation and evaporation
Answer:
filtration and chromatography
Explanation:
I hope this will help you :-)
what is sublimation
Explanation:
Sublimation is the conversion of a substance from the solid to the gaseous state without its becoming liquid. ... Freeze-drying of food to preserve it involves sublimation of water from the food in a frozen state under high vacuum. See also vaporization; phase diagram.
Which element would most likely lose electrons to form positive ions when bonding with other elements?
rubidium (Rb)
gallium (Ga)
argon (Ar)
iodine (I)
The correct answer to the question is Rubidium (Rb)
Rubidium (Rb) is a group 1 element and as such, it can form bond by losing it's valence electron (i.e 1 electron) easily.
Gallium (Ga) is a group 13 element. It can only form bond by losing it's 3 valence electrons.
Argon is a group 18 element. This group has completely filled outermost shell and are very stable. They do not involve in bond formation.
Iodine (I) is a group 17 element. It is more difficult for this group to lose its 7 valence electrons hence, they form bond by accepting 1 electron.
With the above information, we can conclude that Rubidium will most likely lose electron to form bond.
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Answer:
(Question 1)Which element would most likely lose electrons to form positive ions when bonding with other elements?
(Answer) rubidium (Rb)
(Question 2) Which statement about sodium chloride is correct?
(Answer) The sodium atom transfers electrons to the chlorine atoms to form ionic bonds.
(Question 3) Based on their locations in the periodic table, which two elements are most likely to form covalent bonds with each other?
(Answer) nitrogen (N) and oxygen (O)
(Question 4) Which phrase best describes electronegativity?
(Answer) the relative strength with which an element attracts electrons in a chemical bond
(Question 5) Based on the information in the table, which pair of elements would likely form the least polar bonds with each other?
(Answer) bromine and nitrogen
Explanation:
just finished the quick check enjoy UwU
Can someone plz help me? Plzz giving brainliest!
(Plz chose 3 questions)
Answer:
Facts: A D and maybe C I think you are intended to say C
Explanation:
A is certainly not an opinion. It is either true, or it is not. I think it is intended as a fact.
B is an opinion (which I think is true)
C is kind of iffy. It might be true and it might be an opinion. In looking it up, it is factually incorrect. Cats are related to wildcats in the middle east.
D is also iffy. They can just eat disease free rodents. I'd classify it as more opinion than fact.
E. definitely an opinion.
Solid solid soluton example
Explanation:
rice and rice coatssalt and sugarsand and mudwheat flour and corn flourGive an example of a non-biological chemical reaction that involves carbon. Name the process that converts a solid compound into a gas.
Answer: The combustion of methane (CH4) with O2.
Explanation: This is a chemical reaction involving carbon:
CH4 + 2O2 = CO2 + 2H2O
cuantos gramos de soluto y solvente tendra 127 gramos de solición cuya concentración es 14% m/m ayuda para resolverlo
banetshegtsjegsgeheb
What is the approximate mass of one electron?
Answer:
9.1093837015 × 10^−31 kg
Very small mass
Chemical changes can change which properties of a substance?
Group of answer choices
Reactivity
Color
Malleability
All of the above
Answer:
» Reactivity and color
Explanation:
though color is very minor answer because it also relates to a physical property.
[tex].[/tex]
Which of the following are decomposition reactions?
A. CH4 (9) +202 (9) - CO2 (g) + 2H20 (9)
B. N2 (9) + 3H2 (9) ► 2NH3 (9)
C. CaCO3 (s) - Cao (s) + CO2 (9)
D. 2H20 (1) ► 2H2 (9) + O2 (9)
Answer:
C and D
Explanation:
A reaction is said to be decomposed, if the reactant is broken down to liberate single element.
Come up with 2 examples of derived units from everyday life.
Answer:
answer
Explanation:
Area : Square Meters,
Volume : Cubic Meters,
Density : Kilograms per Meter Cube,
Velocity : Meters per Second Squared,
Force : Newtons (Mass multiplied by Acceleration or Mass multiplied by Displacement divided by Time squared)…..
Which of these answers describes a scientific law?
(Pls)
Answer:
big ablsolty long pp
Explanation:
dong
May someone help me with the answer to this question I’ve been stuck on it
Explanation:
No, that would be incorrect
Answer:
There arre two main parts of the atom, the nucleus and the orbital rings. The three subatomic particles are contained in each of these, the proton and neutron together in the nucleus and the electrons orbiting in the rings.
Which of the following statements about alcohols is false?
A. Ethanol is soluble in water.
B. Ethanol has a higher boiling point than ethane.
C. Ethanol produces hydrogen when it burns.
D. None of these
Answer:
It's C. Ethanol produces hydrogen when it burns
When burned, ethanol produces water and CO2.
briefly explain how to separate a mixture of water, kerosene, sawdust and nahso4?
Answer:
Use filtration method lol.
what happens to the food dye in hot water?
Answer:
The food coloring mixes through the hot water faster than it mixes with the cold water. The reason for this is because in hot water, the water molecules have more energy and are moving faster than the molecules of cold water. This makes it way more easier for the dye to get mixed throughout the hot water.
Explanation:
Why do scientists use models of molecules?
A. To research the known effects of the molecule on the environment
B. To explain how electrons, protons, and neutrons are arranged
C. To show the structure of molecules, which are too small to see
D. To design an experimental setup to synthesize molecules
Answer:
C
Explanation:
ANSWER QUICK PLEASE!!!! 25 POINTS
Acrylonitrile and ethyl acetate have the same boiling point: 77.2ºC. In one to two sentences, explain what outcome you would expect if a mixture of these two substances were distilled.
The two substances can never be separated by distillation because distillation depends on difference in boiling point.
Distillation is a separation method that depends on difference in boiling point between two substances.
Usually, the substance having a lower boiling point is collected first as the temperature is gradually raised. The substance having a higher boiling point then follows.
However, since the two substances have the same boiling point, they can not be separated by distillation because they will be converted to vapor simultaneously thereby making separation impossible.
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Which of the following statements is not true about ecosystems?
a. A healthy ecosystem can support an unlimited number of life forms.
b. Predators play a role in balancing the earth's ecosystems.
c. People's activities can improve the health of an ecosystem.
d. The parts of an ecosystem depend on each other.
Answer:
A
Explanation:
though an ecosystem can support life forms,when they become over populated or unlimited there will be competition for food,Shelta and other basic necessities which will lead to many of these life forms dying
A pan containing 20.0 grams of water was allowed to cool from a temperature of 95.0 °C. If the amount of heat released is 1,200 joules, what is the approximate final temperature of the water?
75 °C
78 °C
81 °C
87 °C
Answer:
81 °C
Explanation:
This is a calorimetry question so a few things you will need for this. The calorimetry equation q=mcΔT & the specific heat of water (4.2J/g•°C). Other definitions are:
q = heat added/released by a sample
m = mass of sample
c=specific heat of sample
ΔT = change in temperature
from here we can rearrange the equation to state:
q/(mc) = ΔT
1200J/((20.0g)(4.2J/g•°C)) = ΔT
14°C = ΔT
If the starting temperature was 95.0°C and we know that the temperature was cooled by 14°C then the final temperature of the water would be 81.
Answer:
C. 81 c
Explanation:
took the test :)
Please help me with this chemistry
Answer:
D=1.56g/mL
Explanation:
Density=m/v
D=14.06g/(24mL-15mL)
D=14.06g/9mL
D=1.56g/mL
What are the answers to these?
Answer:
1)physical change
Explanation:
2)chemical change
Classify vodka (composed of 50% water and 50% alcohol).
Answer:
Liquor
Explanation:
HELP! Fill in the blanks:
The net charge of an atom is equal to the difference between the_____
in the atom's nucleus and the_____
Answer:
I don't know
Explanation:
is today your test
gots another for you guys thanks inn advance
Answer:
c. the center of curvature of the two sides of the lens
WILL MARK BRAINLEST IF CORRECT!
1) Burning toast physical or chemical
2) Cooking eggs: physical or chemical
3) Melting butter: physical or chemical
4) Removing the pulp (solid) from the orange juice using a juice strainer.: physical or chemical
5) Cutting the toast with a knife: physical or chemical
6) Digesting the food: physical or chemical
Describe the color change that would be observed in water in left hand beaker
Answer:
is there supposed to be a photo with this?
Explanation:
