Answer:
a. ((100 - 35)/100) times 5.5 grams = 3.575 g
Explanation:
Given that:
The sample of carbon and oxygen = 5.5g
where carbon makes 35% of the mass of the substances.
It implies that oxygen will make: (100 - 35)% = 65%
Suppose y be the mass of the oxygen;
Then:
[tex]y = \dfrac{(100-35)}{100} \times 5.5 \ g[/tex]
[tex]y = \dfrac{(65)} {100} \times 5.5 \ g[/tex]
[tex]y = 3.575 \ g[/tex]
The mass of carbon [tex]= \dfrac{35}{100} \times 5.5 \ g[/tex]
= 1.925 g
4.Calculate the Hydroxide, Hydrogen ion and POH of solution if the PH of solution is 7.b
5.Solution A Has PH =4 and solution B has PH = 7.How many times greater is the Hydroxide ion
concentration in solution A than the Hydronium ion concentration in solution B
the ph is gonna be your value and the 4 is gonna be your main subject
so as the ph is your value u gonna ad your ph and 7 and 4 toghter then multiple your answer 2 times because ph represent multiple and your value
Gather data: Four other pairs of elements in the same chemical family are listed below. List the number of valence electrons in each element. Beryllium Nitrogen Oxygen Fluorine Magnesium Phosphorus Sulfur Chlorine
Explanation:
Valence electrons is the number of electrons in the outermost shell of an atom. For the main group elements, the group number represents the number of valence electrons.
Beryllium
This belongs to the group 2 hence, it has valency of 2.
Nitrogen
This belongs to group 5, hence it has valency of 5.
Oxygen
This belongs to group 6, hence it has valency of 6.
Fluorine
This belongs to group 7, hence it has valency of 7.
Magnesium
This belongs to group 2, hence it has valency of 2.
Phosphorus
This belongs to group 5, hence it has valency of 5
Sulphur
This belongs to group 6, it has valency of 6
Chlorine
This belongs to group 7, it has valency of 7
Answer:
Beryllium: 2 valence electrons.
Nitrogen: 5 valence electrons.
Oxygen: 6 valence electrons.
Fluorine : 7 valence electrons.
Magnesium : 2 valence electrons.
Phosphorus : 5 valence electrons.
Sulphur : 6 valence electrons.
Chlorine : 7 valence electrons.
HELLOSOEOODORODODODORRLKRKLRLRLF
Answer:
I'd say maybe Dangerous? I hope this helps
Answer:
golden is sometimes referred to as shiny and beatitful
Explanation:
0.8 gram of divalent metal was dissolved in 100 CC of 1.28 N HCl and the solution was diluted to to 200 cc. then 50cc of this solution required 54.6 CC of 0.22N NaOH for the neutralization. find the atomic weight of metal .
Answer:
80g/mol is the molar mass of the metal
Explanation:
A divalent metal M reacts with HCl as follows:
M + 2HCl → MCl₂ + H₂
The excess of HCl is titrated with NaOH. Thus, we can solve the moles of HCl that reacts with the metal and the moles of the metal. As the atomic weight is the ratio between the mass and moles of the atom:
Moles NaOH:
0.0546L * (0.22mol / L) = 0.0120 moles NaOH = Moles HCl in excess
For NaOH and HCl solutions, Normality is the same than molarity.
Moles HCl added:
0.100L * (1.28mol / L) = 0.128 moles HCl * (50mL / 200mL) = 0.032 moles
Moles HCl in that react:
0.032 moles - 0.012 moles = 0.020 moles HCl
Moles M:
0.020 moles HCl * (1mol M / 2 mol HCl) = 0.010 moles M
Molar mass M:
0.8g / 0.010mol =
80g/mol is the molar mass of the metalRiboflavin is one of the B vitamins It is also known as B6 and is made up of carbon, hydrogen, nitrogen and oxygen atoms. When 10.0 g of vitamin B6 is burned in oxygen, 19.88 g of CO2 and 4.79 g of H2O are obtained. Another experiment shows that vitamin B6 is made up of 14.89% of N. What is the simplest formula for vitamin B6
Answer:
C₁₇H₂₀N₄O₆
Explanation:
First, we need to determine the percentage of the atoms in the molecule. Then, assuming a basis of 100 we must convert the mass of each atom to moles. Simplest formula is the simplest ratio of atoms presents in the molecule:
%C:
19.88g CO2 * (12.01g/mol C / 44.01g/mol CO2) = 5.425g C
5.425g C / 10.0g * 100 = 54.25% C
%H:
4.79g H2O * (2*1.01g/mol / 18.015g/mol) = 0.537g H
0.537g H / 10.0g * 100 = 5.37%
%N:
14.89%
%O:
100 - 14.89% - 54.25% - 5.37% = 25.49%
Moles of each atom in a basis of 100g:
C: 54.25g * (1mol / 12.01g) = 4.517moles
H: 5.37g * (1mol / 1.01g) = 5.317 moles
N: 14.89g * (1mol / 14.01g) = 1.063 moles
O: 25.49g * (1mol / 16g) = 1.593 moles
Dividing each amount of moles in the lower number of moles (moles N):
C = 4.517mol / 1.063mol = 4.25
H = 5.317mol / 1.063mol = 5
N = 1.063mol / 1.063mol = 1
O = 1.593mol / 1.063mol = 1.5
This ratio multiplied 4 times to obtain whole-numbers:
C = 4.25*4 = 17
H = 5*4 = 20
N = 1*4 = 4
O = 1.5*4 = 6
The simplest formula for vitamin B6 is:
C₁₇H₂₀N₄O₆What are sources of electricity? List as many as you can
Plz Help me plz
Answer:
Solar energy, wind energy, biomass energy.
Explanation:
Does the model represent a chemical reaction? (Image)
Answer:
yes it is a chemical reaction
Explanation:
because the substances combined and made something new
Identify the best practices when storing and using drying agents in the lab.
A. Close the drying agent container whenever it is not in active use.
B. Let the drying agent air out before removing it from the container.
C. Wrap the lid of the drying agent container with tape for storage.
D. Only use drying agent that appears clumpy in its original container.
Answer:
A. Close the drying agent container whenever it is not in active use.
C. Wrap the lid of the drying agent container with tape for storage.
Explanation:
Drying agents also known as desiccants are used in pharmaceutical, food and other manufacturing to keep substances dry. These drying agents are anhydrous and hygroscopic. The right usage of these products requires that they are always stored in an air-tight container.
When they are to be removed from a container containing a solvent, they are to be separated by filtration or decanting.
Which of these has the most kinetic energy?
A. a 25 kg fish tank sitting on a table
B. a .05 g fish swimming in a fish tank
C. a 7,500 kg car parked on a steep hill
D. a 50 kg boulder suspended from a cliff
What is the mass of 3.00 -1023 particles of water? Water has a molar mass of 18.0 g/mol.
3.00 grams
18.0 grams
6.00 grams
9.00 grams
Answer:
bro
Explanation:
guhfuyfouyvyu
Answer:
9.00
Explanation:
I took the test and got it correct ...
A purified protein is in a HEPES buffer at pH 7.0 with 600 mM NaCl. A 1 mL sample of the protein solution is dialyzed against 1.0 L of the same HEPES buffer with 0 mM NaCl. Once the dialysis has come to equilibrium, what is the concentration (in mM) of NaCl in the protein sample
Answer:
Explanation:
Using the dilution formula to determine the final concentration of NaCl in the protein sample.
[tex]M_1V_1 = M_2V_2[/tex]
[tex]600 \ mM \times 1 \ mL= M_2 \times ( 1000\ mL + 1 \ mL)[/tex]
[tex]M_2= \dfrac{600 \ mM \times 1 \ mL}{ ( 1001\ mL)}[/tex]
[tex]M_2= 0.599 \ mM[/tex]
However, when dialysis attains equilibrium, it implies that the sample was dialyzed twice, SO:
[tex]M_2 = \dfrac{600 \ mM\times 1 \ mL}{201 \ mL} = 2.97 \ mM[/tex]
Now, take the concentration as 2.97 mM
Then:
[tex]M_f = \dfrac{2.985 mM \times 1 mL}{201 \ mL}[/tex]
[tex]M_f = 0.01485 \ mM[/tex]
[NaCl] = 0.01485 mM
How many significant figures are in 3.20x10^2 g?
Answer:
3
Explanation:
For numbers with decimals, count the number after the decimal.
How many formula units are contained in 0.57 g Cao?
Which of the following chemical equations correctly
represents between calcium hydroxide and
hydrochloric acid?
+ 2HCI →
CaCl2(aq) + 2H20)
'(aq)
+ HCI →
'(aq)
A Ca(OH)2(aq)
B Ca(OH)2(aq)
C Ca(OH)2(aq)
D Ca(OH)2(aq)
O
caCl(aq)
CaCl2(aq)
+ H2O
+ 2H200
+ HCl(aq)
+ 2HCI
'(aq)
Caci,
2(aq)
+ 2H211)
+
2(g)
Answer:
Ca(OH)2 + HCI
Explanation:
Calcium hydroxides formula is: Ca(OH)2
Hydrochloric Acids formula is : HCI
Please rate and give thanks!
Why is it sometimes not practical to use scale models when representing objects in space?
well space base stars and I'm done know
Explanation:
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Sometimes making a scale model is not practical because it is expensive and takes a lot time to build up for large models of objects. Rebuilding of destroyed scale models is very difficult.
What is scale model ?A physical model that is geometrically comparable to an item is called a scale model . Scale models may be larger than small prototypes like anatomical structures or subatomic particles, but they are often smaller than huge prototypes like cars, buildings, or people.
Mockups are models created at the same scale as the prototype. In addition to being used as toys, scale models are also utilized as tools for engineering design and testing, marketing, and sales, as well as for military strategy and special effects in movies.
The pursuit of model construction as a pastime for artistic purposes is also common. However, it is very expensive and time consuming to create a scale model.
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= 1
= 2
5
= 3
10
= 6
7
8
Write a balanced half-reaction for the reduction of gaseous oxygen (02) to liquid water
to liquid water (H2O) in acidic aqueous solution. Be sure to add physical state symbols
where appropriate.
a
A balanced half-reaction :
O₂(g)+ 4H⁺(aq)+ 4e⁻⇒2H₂O(l)
Further explanationGiven
Reduction of gaseous oxygen (O₂) to liquid water(H₂O)
Required
A balanced half-reaction
Solution
Step 1 : Equalize the number of elements by adding coefficients
Equates element O
O₂(g)⇒2H₂O(l)
Step 2 : Equalize H by adding H⁺ on the opposite side (the deficient area of H).
O₂(g)+ 4H⁺(aq)⇒2H₂O(l)
Step 3 : Equalized the charge using the addition of electrons (e⁻) along the H⁺ field.
O₂(g)+ 4H⁺(aq)+ 4e⁻⇒2H₂O(l)
Atoms of arsenic (As) are often added to silicon (Si) in a process called doping to change the conductivity of the silicon. How does the addition of arsenic change the conductivity of silicon?
a) An atom of arsenic has one fewer valence electron and more electron shells than an atom of silicon, so the conductivity decreases because the arsenic atom gains an electron.
b) An atom of arsenic has one more valence electron and more electron shells than an atom of silicon, so the conductivity decreases because the arsenic atom loses the electron.
c) An atom of arsenic has one fewer valence electron and fewer electron shells than an atom of silicon, so the conductivity increases because the arsenic atom gains an electron.
d) An atom of arsenic has one more valence electron and more electron shells than an atom of silicon, so the conductivity increases because the arsenic atom loses the electron.
HAD TO POST THIS THIS BC THE OTHER POSTED IS WRONG
Answer:
d) An atom of arsenic has one more valence electron and more electron shells than an atom of silicon, so the conductivity increases because the arsenic atom loses the electron.
Explanation:
This is an example of a n-type semiconductor. The additional electron introduced to the 'grid' of silicon atoms causes an increase in the conductivity of the silicon. This additional electron is introduced as arsenic loses its extra electron.
Answer:
D is the answer, the other one is wrong.
Explanation:
Question 2 of 10 A chemist has a block of copper metal (density is 8.96 g/mL). They drop the metal into a graduated cylinder containing water, and find the volume change is 2.90 mL. What is the mass of the block, in grams? h
Answer:
m = 25.98 g
Explanation:
Given data:
Density of copper metal = 8.96 g/mL
Volume of copper metal block = 2.90 mL
Mass of copper metal block = ?
Solution:
The volume of given block of copper is equal to the volume change of water by adding this block.
Density formula:
d = m/v
by putting values,
8.96 g/mL = m/ 2.90 mL
m = 8.96 g/mL × 2.90 mL
m = 25.98 g
A copper wire is 44.85 cm long and weighs 1.521 g. The density of copper is 8.933 g/cm3.
What is the radius of the wire in millimeters?
What is the diameter of the wire?
Answer:
i am so sorry
Explanation:
The density of copper is If a sample 8.933 g/cm3. If copper has a volume of 12.993 cm^3. Then the mass will be 136.29 gram.
How can we calculate the mass from density and volume?Density is defined as the mass per unit volume it means that mass present in 1 meter cube is called density. The S.I unit of density is kg/m^3 and in C.G.S it is gram/cm^3
So, In above question can understand that density, mass, and volume all are convert to each other it means that if we know any two variable then third one will be calculated easily.
Mathematically,
Formula for density will be as mentioned below:-
Density = Mass/Volume.
From above formula we can calculate mass which is as follows:-
Mass = Volume × Density.
S.I unit of mass is kilograms and C.G.S unit is gram.
So In above question
Density = 8.933 gram/cm^3
Volume = 12.993 cm^3
So from above formula
Mass = Density × volume
= 10.49 × 12.993
= 136.29 gram
= 0.13629 kilogram
So Mass is equal to 136.29 gram or 0.136 kilograms.
Therefore,The density of copper is If a sample 8.933 g/cm3. If copper has a volume of 12.993 cm^3. Then the mass will be 136.29 gram.
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How many moles of hydrogen react with 4.5 moles of oxygen to synthesize water?
Answer:
9moles of hydrogen gas
Explanation:
To solve this problem, we write the reaction expression first;
2H₂ + O₂ → 2H₂O
We have been given the number of moles of oxygen gas to be:
Number of moles of oxygen gas = 4.5moles
From the balanced reaction expression:
1 mole of oxygen gas reacts with 2 moles of hydrogen gas
4.5moles of oxygen gas will react with 4.5 x 2 = 9moles of hydrogen gas
Please help ASAP
Read thing for the question thanks!!
Answer:
JOSHUA
Explanation:
JOSHUA
Which energy transformation occurs when you rub your hands together to warm them?
kinetic energy to radiant energy
thermal energy to kinetic energy
thermal energy to potential energy
want energy to thermal energy
Explanation:
The answer is thermal energy/ kinetic energy.. because friction on hands promotes thermal energy. because you want your hands 2 be warm, rubbing them 2gether creates heat and absorption of heat thru the skin which skin is susceptible to warm, humans can put hands under arm pits to warm hands, without any available heat source..
How many molecules are in 15 moles of CO2?
There are 90.345 x 10^23 molecules in 15 moles of CO2.
What is Avogadro's number?Avogadro's number is the number of units, atoms or molecules in one mole of a substance which is equals to 6.02214076 × 1023. This number is also known as the Avogadro constant.
This means that one mole of a substance is equals to 6.02214076 × 1023 atoms, ions or molecules then 15 moles is equals to 90.345 x 10^23 molecules so we can conclude that there are 90.345 x 10^23 molecules are in 15 moles of CO2.
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How do the valence electrons of an element determine how they will combine with other elements to produce a compound? Please help this is urgent :)
Answer:
See explanation
Explanation:
The valence electrons are electrons found on the valence (outermost) shell of an atom.
When an atoms form compounds, there is an exchange of valence electrons between the atoms of one element and the atoms of another element.
Let us consider a typical example, sodium has one valence electron and chlorine has seven valence electrons. This means that chlorine needs one electron to complete its octet while sodium needs to release one electron in order to attain the octet structure.
So, sodium gives out its one electron and becomes a stable sodium ion and chlorine accepts that electron and becomes a stable chloride ion. This is how the compound sodium chloride is formed.
1. All the following are correctly balanced except -
A. 2C2H2 + 502 4CO2 + 2H20
B. 4Fe + 302 – 2Fe2O3
C. NaHCO3 Na2CO3 + H2O + CO2
D. 2CH,OH + 302 2C02 + 4H20
Which element is more electronegative, Ge or Bi
Answer:
Ge is more electronegative
Explanation:
7. You are about to perform some intricate electrical studies on single skeletal muscle fibers from a gastronemius muscle. But first, you must prepare 6L of a 170 mM NaCl solution in which to bath the isolated muscle during your studies. How many grams of NaCl must you weigh out on the lab balance to prepare this bath solution
Answer:
58.61 grams
Explanation:
Taking The molecular weight of NaCl = 58.44 grams/mole
Determine how many grams of NaCl to prepare the bath solution
first we will calculate the moles of NaCl that is contained in 6L of 170 mM of NaCI solution
= ( 6 * 170 ) / 1000
= 1020 / 1000 = 1.020 moles
next
determine how many grams of NaCl
= moles of NaCl * molar mass of NaCl
= 1.020 * 58.44
= 58.61 grams
What is the charge is the ion when lithium reacts with chlorine
Identify the Sun activity that travels from one sunspot to another sunspot.
Group of answer choices
Prominence
corona mass ejection
solar wind
solar flare
Answer:
solar flair I think I'm not sure
an organic pesticide was decomposed by an oxygen combustion procedure to convert the chlorine in the molecule to water soluble chloride the chloride was then precipitated as AgCl A 0.7715 gram precipitate was obtained from 500 grams of pesticide Calculate the percentage chlorine in the pesticide
Answer:
0.0382%
Explanation:
Given that:
Silver chloride = AgCl
Molar mass of AgCl = (107.87 + 35.5) = 143.37 g/mol
Chlorine, Cl = 35.5
143.37g/mol of AgCl = 35.5 g of Cl
Hence, 1 g AgCl will give ; (35.5 / 143.37)
1g AgCl = 0.2476 g Cl
In 0.7715 g AgCl, ; (0.2476*0.7715) g Cl
= 0.1910 g Cl
Therefore, percentage of Cl in 500g sample:
(Mass of Chlorine / mass of sample) * 100%
(0.1910 / 500) * 100%
0.000382 * 100%
= 0.0382%