Answer:
3 Cu + 8 HNO3 --> 3 Cu(NO3)2 + 2 NO + 4 H2O
Explanation:
Make sure both sides are equal
3 Cu + 8 HNO3 --> 3 Cu(NO3)2 + 2 NO + 4 H2O
// start by those elements that change their oxidation degree
Cu and N
// also you can write reduction-oxidation reactions
[tex]Cu^{0}[/tex] + 2 [tex]e^{-}[/tex] --> [tex]Cu^{-2}[/tex] | 2
[tex]N^{+5}[/tex] - 3 [tex]e^{-}[/tex] --> [tex]N^{+2}[/tex] | 3
// write the numbers of electrons that are lost/gained as the coefficients of the opposite elements
// then check if H and O are the same on both sides
// adjust if they aren't.
Answer:
Explanation:
3Cu + 2HNO3 --> 3Cu(NO3)2 + 2NO + 2H2O
How many atoms are in 11.5 g of Hg?
A. 5.73 x 10^-2 atoms
B.3.45 atoms
C.3.45 x 10^22 atoms
D. 5.73 atoms
Please help with chem ASAP
Answer:
Imagine Dragon
Explanation:
These balls across yo face
Gottem
What is the boiling point of water?
A. 0°C
B. 50°C
C. 70°C
D. 100°C
Answer:
D) 100*C
Explanation:
Answer:
A. 0°C
Explanation:
El agua se evapora a los 0 grados
Determine if you can swim in 1×10^27 molecules of water
what is a second degree burn
How do magnets move objects?
Answer: Magnets have a force which is known as no contact force. This force tries to attract the metallic objects near it, which makes it move.
Explanation:
explain the factor of a skeleton system
1. Which of the following is the most important function of the microscope?
A. measuring specimen
B. magnification of the specimen
C. photographing the specimen
D. locating and viewing the specimen
image or
1. Which of the following seismic waves is detected first by the seismograph?
A L-waves B P-waves
CR-waves D.S-waves
Answer:
AL- waves
Explanation:
because it is famousable
what is used to make the dry cells ????
Answer: The parts of a dry cell battery are as follows: at the center is a carbon rod called a cathode. The cathode is surrounded by an electrolyte paste. The paste and cathode are surrounded by a separator before finally being sealed within a zinc cylinder.
Explanation: A diagram is show below
4.Which scientist described the electrons as traveling in certain orbits or energy levels?
a.Dalton
b.Rutherford
c.Thomson
d.Bohr
5.In a famous experiment, scientists bombarded a very thin gold (Au) foil with positively charged alpha particles. They found that most of the alpha particles passed right through the Au foil. However, a few of the alpha particles were deflected or bounced back toward the source. How did these scientists explain their results?
a.Negative charges are spread throughout the atom.
b.Negative charges are located in the tiny nucleus of the atom.
c.Positive charges are located in the tiny nucleus of the atom.
d.Positive charges are spread throughout the atom.
6.The atomic mass represents the weighted average of an element’s
a.Ions
b.mass numbers
c.atomic numbers
d.isotopes
7.The number of protons is represented by the element’s
a.atomic number
b.mass number
c.atomic mass
d.isotope
8.The number of protons plus neutrons is represented by the
a.atomic number
b.mass number
c.atomic mass
d.isotope
9.How many valence electrons would an atom of Chlorine have?
a.2
b.3
c.7
d.8
10.An element is found to have 2 electrons in the 3rd energy level. What is this element?
a.Boron
b.Magnesium
c.Fluorine
d.Argon
11.Which shows the order of decreasing atomic size?
a.Si, Al, Mg, Na
b.I, Br, Cl, F
c.Be, Mg, Ca, Sr
d.C, P, Se, I
12.Which of the following elements has the highest ionization energy and why?
a.Argon because it has more protons in the nucleus.
b.Argon because it has a full valence shell.
c.Chlorine because it only needs one valence electron to fill its valence shell.
d.Chlorine because it attracts electrons better.
13.Which shows the order of increasing ionization energy?
a.Si, Al, Mg, Na
b.Ga, Ge, As, Se
c.Be, Mg, Ca, Sr
d.F, Cl, Br, I
14.Identify the reason why atoms decrease in size(atomic radius)across a period on the Periodic Table.
a.Gravity pulls the electrons in towards the nucleus.
b.Increase in energy levels increases the attraction and thus pulls electron cloud in.
c.Increasing strong positive nuclear charge from the nucleus pulls in the negative electron clouds and increases with the increase in protons and electrons.
d.Electrons lose energy and collapse with an increasing number of electrons and protons.
15.What is the shielding effect?
a.The neutrons shield protons from the attraction of the electrons from the first energy level.
b.Valence electrons are shared equally between atoms.
c.The repulsion of electrons in the same energy level.
d.The inner-core electrons shield outer-core electrons from the attraction to the atom’s nucleus.
16.Which statement is an accurate description of elements from Period 3 on the periodic table?
a.It contains elements with the same number of 3 protons.
b.It contains elements with the same number of3valence electrons.
c.It contains elements with the outermost protons in the same 3rd energy level.
d.It contains elements with the outermost electrons in the same 3rd energy level.
17.The column that an element is located in tells us
a.the total number of valence electrons an atom has.
b.the total number of energy levels an atom of that element has.
c.the highest energy level an atom of that element has.
d.both b & c.
18.The Halogen family of elements all have 7 valence electrons. Which column would they be in?
a.01 (IA)
b.02 (IIA)
c.4 (IVA) or 14
d.7 (VIIA) or 17
19.The Alkali and Alkaline Earth metals belong to which columns, respectively?
a.Column IA & IIA
b.Column VIIA & Column VIIIA
c.Column IIIA & IVA
20.What do carbon and silicon have in common?
a.They belong to the same column (family), therefore they have the same number of valence electrons.
b.They belong to the same column (family), therefore they have the same number of total electrons.
c.They belong to the same column (family), therefore they have the same number of energy levels.
d.They belong to the same column (family), therefore they have the same number of protons.
21.Electromagnetic radiation can take the form of which of the following types of waves
a.Heat
b.Light
c.Ultraviolet
d.All of the above
24.In order to go to a lower energy orbit, an electron
a.Must disappear
b.Must combine with other electrons
c.Lose energy of a specific amount
d.Must be transferred to another atom
25.Please choose the correct sequence that describes the excitement of an atom.
1. Such an electron transition raises the atom from the ground state to the excited state.
2. When energy is added to an atom from an outside source, its electrons move to a higher energy level (orbit)
3. As a result, the atom emits a photon.
4. When the atom is in an excited state, the electron can drop from the higher energy level to a lower energy level.
a.1, 2, 3, 4
b.4, 3, 2, 1
c.2, 1, 4, 3
d.3, 4, 1, 2
How many grams of magnesium oxide would be produced if 3.8 grams of magnesium reacted completely with 2.1 grams of oxygen
Answer:
5.3g of MgO would be produced
Explanation:
Based on the chemical reaction:
2Mg(s) + O₂(g) → 2MgO(s)
1 mole of Mg reacts per mole of oxygen.
To solve this question we need to convert the mass of each reactant to moles in order to find limiting reactant using the chemical equation:
Moles Mg -Molar mass: 24.305g/mol-:
3.8g Mg * (1mol / 24.305g) = 0.1563moles Mg
Moles O₂ -Molar mass: 32g/mol-:
2.1g O₂ * (1mol / 32g) = 0.0656 moles O₂
For a complete reaction of 0.0656 moles of O₂ are required:
0.0656 moles O₂ * (2 mol Mg / 1mol O₂) = 0.132 moles Mg
As there are 0.1563 moles of Mg, Mg is the excess reactant and O₂ the limiting reactant.
0.0656 moles O₂ produce:
0.0656 moles O₂ * (2 mol MgO / 1mol O₂) = 0.132 moles MgO
The mass is -Molar mass MgO: 40.3g/mol-:
0.132 moles MgO * (40.3g / mol) =
5.3g of MgO would be produced
Is it okay if you help me? I'm kind of in a tight spot here. Tysmmmmmmmmmmmmm o(❁´◡`❁)o!!
Answer:
C. Remains constant
Explanation:
Hope this helps (:
1) Write the symbol and charge for each individual ion
2) Balance the charge so that they equal to zero
3)Write the formula based on how many of each ion you used in step 2
6) Nitrogen and Barium
7) strontium and fluorine
8) iodine and calcium
9) magnesium and sulfur
10) Sulfur and aluminum
N -3
Ba +2
Sr +2
F -1
I -1
Ca +2
Mg +2
S -2
S -2
Al +3
//
Ba3N2
SrF2
CaI2
MgS
Al2S3
//
I don't really understand 2.
Write the formula and determine the percent by mass of the salt in barium hydroxide octahydrate *
(show work)
Answer:
315.51g/mol
Explanation:
137(33 + (16.00 + 1.01) 2 + 8 [1.01 (2) + 16.00] = 315.51g/mol
which of the following is and example of a chemical property?
Choose the aqueous solution below with the highest boiling point. These are all solutions of nonvolatile solutes and you should assume ideal van't Hoff factors where applicable.
The question is incomplete, the complete question is;
Choose the aqueous solution that has the highest boiling point. These are all solutions of nonvolatile solutes and you should assume ideal van't Hoff factors where applicable. 0.100 m C6H12O6 0.100 m AlCl3 0.100 m NaCl 0.100 m MgCl2 They all have the same boiling point.
Answer:
AlCl3 0.100 m
Explanation:
Let us remember that the boiling point elevation is given by;
ΔTb = Kb m i
Where;
ΔTb = boiling point elevation
Kb = boiling point constant
m = molality of the solution
i = Van't Hoff factor
We can see from the question that all the solutions possess the same molality, ΔTb now depends on the value of the Van't Hoff factor which in turn depends on the number of particles in solution.
AlCl3 yields four particles in solution, hence ΔTb is highest for AlCl3 . The solution having the highest value of ΔTb also has the highest boiling point.
I NEED HELP ASAP, If you help me I’ll give you Brainlist [Calorimetry and specific heat lab]
I don’t know how to calculate the error %
The formula is:
%Error = [I Accepted value-Experimental value I / Experimental value] x 100 can someone please PLEASE help me :(
Answer:
Explanation:
I gave this formula as
What you should get - what you got
--------------------------------------------------- * 100
What you should get
Suppose you are talking about the specific heat of copper and you did a lab and did it fairly well and the specific heat came out to be 0.33
That's what you got, 0.33
What you should get is 0.35 according to the table you've given us.
% error = 0.35 - 0.33
-------------- * 100
0.35
% error = 0.02 * 100/ 0.35
% error = 2/0.35
% error = 5.71
Now here is the really hard part. You have to decide what a positive error is and what a negative error.
A positive error using this formula means you are too low.
A Negative error means that you are too high, just the opposite of what you might think.
Can you show us the experimental value?
So basically, the accepted value would be under the Specific heat capacity of metal (e.g. 0.90, 0.35, 0.44, 0.12).
Your experimental value would be the specific heat capacity that you got from the lab.
You would first substract the experimental value from the accepted value
[tex]accepted \: value - experimental \: value [/tex]
and then you would divide the result by the experimental value
[tex]result \div experimental \: value[/tex]
and then, you would multiply the result of that by a hundred to get your percentage
[tex]result \times 100 = \% \: error[/tex]
//
The image shown is an example.
0.90 is our accepted value.
0.88 is our experimental value.
The overall percentage error I got is %2.27
list 10 uses of composite
Aerospace
Thermoset composites are being specified for wings, fuselages, bulkheads, and other applications in commercial, civilian and military aerospace applications.
Appliance/Business
Thermoset composite are being used in frames, equipment panels, handles and trims in appliances, power tools, business equipment and many other applications.
Thermoset composites for the appliance industry are used in washers, dryers, refrigerators, freezers, ranges, ovens, dishwashers for components that include control panels, handles, knobs, vent trims, side trims, motor housings, kick plates and many others.
Automotive/Transportation/Farm/Construction
Composites are now being used in vehicle and equipment applications, including, panels, frames, interior components and other parts.
Civil Infrastructure
Some composite infrastructure applications include buildings, roads, bridges and pilings.
Construction
Thermoset composites are replacing many traditional materials for home and offices architectural components including fixtures, doors, wall panels, roofing, window frames, moulding, vanity sinks, shower stalls and even swimming pools.
Corrosive Environments
Composites are ideal for applications in corrosive environments, such as chemical processing plants, pulp and paper converting, oil and gas refineries and water treatment facilities. Common applications include fans, grating, tanks, ducts, hoods, pumps and cabinets.
Electrical
With strong dielectric properties including arc and track resistance, Thermoset components include substation equipment, microwave antennas, standoffs and pole line hardware and printed wiring boards. Applications and components include switchgear, motor controls, standoff insulators, control system components, circuit breakers, arc chutes, arc shields, terminal blocks, terminal boards, metering devices, bus supports and lighting components.
Marine
With their corrosion resistance and light-weighting attributes, Marine composite applications include boat hulls, bulkheads and other components for military, commercial and recreational boats and ships.
magnesium__ + sulfuric acid goes to form magnesium sulfate+ water + carbon dioxide
Answer:
carbonate
Explanation:
this is because when carbonates react with acid they form carbon dioxide and water and respective metal oxide
Please help: A complete moon cycle is how many weeks
Answer:
29.5 days
Explanation:
its 29.5 days i hope it helps
Answer:
The Moon takes 27.3 days to orbit Earth, but the lunar phase cycle (from new Moon to new Moon) is 29.5 day
Which changes would cause an increase in the resistance of a wire? Check all that apply.
increasing its temperature
decreasing its temperature
using a longer wire
using a shorter wire
m using a thicker wire
using a thinner wire
Answer:
Increasing its temperature.
Longer
and thinner
Explanation:
e2021
The resistance of a wire increases by increasing its temperature, using a longer wire and using a thinner wire.
Resistivity of a wireThe resistivity of wire describes the opposition to the flow of current in the wire.
[tex]R = \frac{\rho L}{A} \\\\\rho = \frac{RA}{L} \ (ohm-meter)[/tex]
where;
R is the resistance (ohms)ρ is resistivity of the wire (ohm-meter)L is length of the wire (m)A is area of the wire (m²)From the formula above, the resistance of a wire increases with
increase in the length of the wiredecrease in thickness (radius) of the wireincrease in temperatureLearn more about resistance of a wire here: https://brainly.com/question/469388
When calculating the AH of a reaction, why is it important that you include the correct stale symbols in your balanced chemical equation?
Answer: c. so that you use the correct energy states
Explanation:
Enthalpy is the energy release or energy produced when a chemical reaction is carried out.
Enthalpy change is calculated by substracting the energy of reactants from the energy of products.
[tex]\Delta H=H_{products}-H_{reactants}[/tex]
As the energies are different for different states and thus the correct stale symbols in your balanced chemical equation must be given so that we use the correct energy values.
Which of these is a biotic factor of an ecosystem?
A) Crystals of salt
B) Rays of sunlight
C) Grains of Sand
D) Strands of seaweed
Which process directly moves nutrients from animals to the air?
D.Breathing
Oxygen obtained through respiration is used by cells in the cellular respiration process to obtain energy. Each animal has a different way of performing gas exchange, but we can say that it is through breathing that all animals move nutrients directly into the air through breathing
1) In which state of matter will particles move the fastest?
Answer:
Gases
Explanation:
The particals will move around rapidly in all directions.
Name the acid and the base from which the salt calcium sulphate is formed. also write the
balanced chemical equation for the chemical reaction
Answer:
Calcium Carbonate base and Sulphuric acid.
CaCO3 and H2SO4
Answer:
Skeletal equation : Ca(OH)2 + H2SO4 ----> CaSO4 + H2O
Balanced equation : Ca(OH)2 + H2SO4 ---> CaSO4 + 2H2O
Hope it helps
How cold does it really get on Pluto's moon, Charon? (I know this is not a Chem question per se, but is there no Earth Science, nor Space, nor Astronomy, nor General Science category on Brainly?)
Answer:
Explanation:
After various studies and experiments conducted on Pluto's moon, Charon it has been determined that it gets to minus 459.67 degrees Fahrenheit which would be equivalent to minus 273.15 degrees Celsius. This is the coldest temperature that scientists have registered for Charon. This temperature is nearing absolute zero and puts it colder than Pluto itself since Pluto's temperature is believed to get to minus 400 degrees Fahrenheit which is equivalent to minus 240 degrees Celcius.
1. Which word has the same phoneme as grew, rude, and truth?
A. thumb
B. sure
C. look
D. scoot
Answer:
B-Sorry if this isn't right :/ Good luck.
Explanation:
Answer:
D. Scoot
Explanation:
Grew, Rude and truth all have the sound /OO/ scoot follows that pattern.
A gas has a volume of 500cm3 when a pressure of 100,00N is exacted on it what will be it's volume if the pressure is changed to 150mm mecury at same temperature
Answer:
See explanation below
Explanation:
At first sight, it seems that the innitial pressure of 100,00 N would be 100,00 N/m² because pressure does not have units of newton alone. If this is true, then the calculations are the following (If it's not, but it's actually mm Hg, then skip the part of the conversion, and just do the procedure of solving for the volume).
The innitial pressure is 100 N/m² or simply 100 Pa. As the second pressure is in mm Hg, let's convert the Pascal units to mm Hg:
1 Pa -----> 0.007501 mm Hg
100 ---------> X
X = 100 * 0.007501 / 1 = 0.7501 mmHg
Now that we have the innitial pressure in mm Hg, and the temperature remains constant, we use the Boyle's law to solve for this:
P₁V₁ = P₂V₂
V₂ = P₁V₁ / P₂
Using this expression, let's solve for V₂:
V₂ = 0.7501 *¨500 / 150
V₂ = 2.5 cm³
Now, it's the innitial pressure is 100 mm Hg then the volume:
V₂ = 100 * 500 / 150
V₂ = 333.33 cm³
Check the units of the innitial pressure, one of these results should be the correct answer. If it's not, then please post again the question with the correct units.
Hope this helps
