Answer:
Any two used of mixtures are 1) sand and water 2) sugar and salt
Explanation:
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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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
Which type of bond and how many bonds would occur as carbon dioxide (CO2) is formed from carbon in Group IVA and oxygen in Group VIA?
three metallic bonds
two ionic bonds
four covalent bonds
one covalent bond
Four covalent bonds are formed as carbon dioxide (CO2) is formed from carbon in Group IVA and oxygen in Group VIA.
The periodic table is composed of eighteen groups and eight periods. The common thread that holds all the elements in a group is that they all have the same number of valence electrons in their atoms. The elements in the same period all have the same highest energy level.
Oxygen in group Group VIA has six valence electrons while carbon in group Group IVA has four valence electrons. Hence, the chemical bond in carbon dioxide CO2 must contain four covalent bonds as shown in the image attached to this answer.
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Answer:
Four Covalent bonds
Explanation:
Behind your house, there's a gorgeous pond filled with frogs. You notice that the frogs behind Mr. Archer's house often have three legs. You start wondering if the fertilizer that Mr. Archer uses for his lawn is causing the deformities in the frogs. You collect 10 frogs and put the special fertilizer in their container (Group A). You put another 10 frogs and place them in a different container with just water (Group B). A week later, 7 out of 10 of the frogs in group A grew only three legs. The frogs in group B grew four legs.
What was the control group?
Answer:
Group B is the control group
Explanation:
In an experiment, a control group is the standard to which comparisons are made in an experiment.
Classify the items based on whether they are or are not matter.
Answer:
Matter:
toothpaste
gasoline
bacteria
cell
Not matter:
happiness
sound
Explanation:
Matter is something that has mass and volume. Happiness is just a feeling, it doesn't exist in 3d world. Sound is a wave or just the movement of matter (particles of matter). Others have masses and volumes.
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)…..
Someone plz help me giving brainliest m
Answer:
C
Explanation:
it would be the best action because questions are important when looking at designs/creating them.
in which sell duplet rule is applied, why?
Answer:
its in explanationExplanation:
the tendency for items have 2 electrons in their outermost shell by interacting with others items through electron sharing or transfer is known as duplet rule. if an atom has 2 electrons in it's outermost shell then it is called duplet rule and if a 8 electrons in it's outermost shell than it is called octet rule .
What are the answers to these?
Answer:
1)physical change
Explanation:
2)chemical change
Helppppp….. is this right?
Answer:
Yes, it is correct.
Explanation:
400 cm = 4 m
40 m = 40 m
0.4 km = 400m
Therefore, 400 cm < 40 m < 0.4 km
Answer:
Explanation:
400 centimeter....... smallest
0.4 kilometer .............. middlest
40 meter..................... greatest
Which of the following are considered physical properties of a substance?
Color and odor
malleability and hardness
melting and boiling points
all of the above
hi <3
the correct option would be all of the above
hope this helps :)
Solid solid soluton example
Explanation:
rice and rice coatssalt and sugarsand and mudwheat flour and corn flourA decrease in temperature reduces the volume of gas
a
Chemical Change
b
Physical Change
Answer:
Chemical change.
Hope this helps you.
Pb(NO3)2 + ? = PbCl2 +?
Answer:
HCL, H2
Explanation:
Assuming this is a Redox reaction, we know that metal + acid = salt + hydrogen therefore we can say it is HCL and H2
Is it correct or wrong
Answer:
i think correct
Explanation:
i am not sure but i hope it will help you
an element consists of 1.40% of an isotope
Answer:
I think it's lead (pb). Hope this helps.
Answer:
lead
Explanation:
i got the total but can’t get these ???
Answer:
Volume of heptane in cylinder = 51.2mL
Volume of water = 33mL
Explanation:
Density(g/mL) = mass/ Volume
》Volume = mass/ Density
Please prompt me if I'm wrong in my workings. Hope this helped.
In a titration, when the number of moles of hydrogen ions equals the number of moles of hydroxide ions, what is said to have happened?
The equivalence point has been reached.
The point of neutralization has been reached.
The end point has been reached.
Tyrone and Valerie wanted to determine what feature of a paper airplane would cause it to fly the farthest. Tyrone made his airplane with longer wings than Valerie's airplane. Valerie's airplane had shorter wings than Tyrone's. After testing the two airplanes several times, the data shows that wider wings help airplanes fly farther than shorter wings.
Which characteristic of science is missing from this experiment?
The question is not testable because paper airplanes are always changing.
The phenomenon is not observable because air resistance changes.
The experiment is not replicable because controlled variables are not included.
The results are not reliable because the airplanes were only tested one time.
The characteristic of science that is missing from this experiment is that "the results are not reliable because the airplanes were only tested one time".
Some of the characteristics of science include objectivity, verifiability , reliability, accuracy, observable, precision etc.
Based on the question asked, the results of the experiment are not reliable due to the fact that the the airplanes were only tested one time. The airplanes should have been tested multiple times to show that they are reliable.
In conclusion, the correct option is D.
Read related link on:
https://brainly.com/question/5500131
Answer:
D
Explanation:
Classify vodka (composed of 50% water and 50% alcohol).
Answer:
Liquor
Explanation:
A researcher wants to conduct an experiment to see how the amount of breakfast a student eats
affects their performance in school. He makes 2 groups, one group consumes 300 calories in
the morning while the second group does not eat breakfast at all. After 2 weeks he compares
the students test scores and every student takes the same tests. Identify the following:
a. Control Group:
b. Independent Variable:
c. Dependent Variable:
The control group are the students who eat no breakfast. The independent variable is the consumption of breakfast. The dependent variable is the performance of students in school.
In an experiment, the control group is the group that did not receive the treatment. The treatment in this case is the consumption of breakfast. Hence the group that did not consume breakfast is the control group.
The independent variable is the variable that is being manipulated and its effect evaluated. The manipulated variable here is consumption of food.
The dependent variable is the variable that is being measured. In this case, it is the performance of students at school.
Learn more; https://brainly.com/question/967776
Which two elements have the same number of energy levels with electrons in them?(1 point)
A_ krypton and neon
B_ boron and oxygen
C_ lithium and francium
D_ neon and sodium
Its B) Boron and Oxygen
The correct answer is B.
boron and oxygen have the same number of energy levels with electrons in them.
The energy level of an element is the region around the nucleus where its electron is likely to be, this corresponds to the period of the element in the periodic table.
Elements found in period 1, have one energy level.
Elements found in period 2, have two energy level.
Examples of elements found in period 2 include:
lithium, beryllium, boron, carbon, nitrogen, oxygen, fluorine, and neonIn the given options, only option B contains two elements with 2 energy level.
Thus, boron and oxygen have the same number of energy levels with electrons in them.
Learn more here: https://brainly.com/question/18616411
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.
If a sample of water has a mass of 200g and the final solution has a mass of 230g, how much solute dissolved in the water?
Second ionization energies are always _____ than first ionization energies because the remaining electrons are attracted _____ strongly as the positive charge on the ion increases. A large jump in ionization energies is always observed after the _____ electrons have been removed.
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.
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:
please mark me brainleast
You just created the equality 1 fluid oz f l u i d o z = 29.7 mL m L . Use this equality to determine how many ounces of water will be measured using the measuring cup introduced before Part A when making the cake. Keep in mind that the level of precision for the measuring cup is to the half-ounce as you round your answer.
The equality of both units (i.e. mL and ounces) implies they measure the same quantity, and they can be converted between one another.
Given that:
[tex]1 fl\ oz = 29.7mL[/tex]
The measurement in part A is not given. So, I will use an assumed value to provide an explanation.
Assume that the amount of water measured using the measuring cup in part A is 10mL
The equivalent number of ounces (x) is calculated as follows:
[tex]1 fl\ oz = 29.7mL[/tex]
[tex]x = 10mL[/tex]
Cross multiply
[tex]x \times 29.7mL = 1fl\ oz \times 10mL[/tex]
Cancel out common units
[tex]x \times 29.7 = 1fl\ oz \times 10[/tex]
[tex]x \times 29.7 = 10fl\ oz[/tex]
Divide both sides by 29.7
[tex]x = \frac{10}{29.7}fl\ oz[/tex]
[tex]x = 0.3367 fl\ oz[/tex]
Approximate to the nearest half
[tex]x = 0.5 fl\ oz[/tex]
This means that the equivalent amount of water is 0.5 ounces
What if the measurement is 55mL.
We apply the same steps, as follows:
[tex]1 fl\ oz = 29.7mL[/tex]
[tex]x = 55mL[/tex]
Cross multiply
[tex]x \times 29.7mL = 1fl\ oz \times 55mL[/tex]
Cancel out common terms
[tex]x \times 29.7 = 1fl\ oz \times 55[/tex]
[tex]x \times 29.7 = 55fl\ oz[/tex]
Divide both sides by 29.7
[tex]x= \frac{55}{29.7 }fl\ oz[/tex]
[tex]x= 1.85185 fl\ oz[/tex]
Approximate to the nearest half
[tex]x = 2fl\ oz[/tex]
This means that the equivalent amount of water is 2 ounces
Read more about unit conversions at:
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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
4. Which of the following are not able to
travel through empty space?
A. gamma rays
C. sound waves
B. ultraviolet waves
D. light waves
Answer:
C.Sound waves.
Hope it helps you.