11. A mixture of magnesium powder and lead (II) Oxide will react vigorously when heated
but no reaction occurs when a mixture of magnesium oxide and lead powder are heated,
a) Explain the observation.
b Which of the two substances, magnesium or lead(IT) Oxide is;
i) Oxidized in the reaction?
ii) Oxidizing agent?
C Which is the most reactive metal
Please help
Answer:
Explanation:
The reaction is violent but safe, provided the procedure is followed exactly. ... Chemicals. Magnesium powder (HIGHLY FLAMMABLE), 0.25 g (note 4); Copper(II) oxide powder ... top must NOT be hot when the magnesium powder/copper oxide mix is added. ... After one or two minutes (be patient) a vigorous reaction occurs.
please help me :)
( check the photo! )
Answer:
plastic rays i think the matetial that can widely recycle
24
Select the correct answer.
Which statement is correct?
A.
When the concentration of the reactant decreases, the cell potential increases.
B.
When the concentration of the reactant decreases, the cell potential does not change.
C.
When the concentration of the reactant increases, the cell potential decreases.
D.
When the concentration of the reactant increases, the cell potential increases.
E.
When the concentration of the reactant increases, the cell potential does not change.
Answer:
the answer is b
Explanation:
8. Calculate the pH of a solution if the [OH-] concentration is 0.015 M.
A) 1.82
B) 8.82
C) 12.18
D) 4.32
Answer:
1.82
Explanation:
pH is given by the equation
How many liters of ammonia gas can be formed from 24.5 L of hydrogen gas at STP?
Answer: 16.3 L of ammonia gas can be formed from 24.5 L of hydrogen gas at STP
Explanation:
According to avogadro's law, 1 mole of every substance occupies 22.4 L at STP and contains avogadro's number [tex]6.023\times 10^{23}[/tex] of particles.
The balanced chemical equation is:
[tex]3H_2+N_2\rightarrow 2NH_3[/tex]
According to stoichiometry :
[tex]3\times 22.4=67.2L[/tex] of [tex]H_2[/tex] produce = [tex]2\times 22.4=44.8L[/tex] of [tex]NH_3[/tex] at STP
Thus 24.5 L of [tex]H_2[/tex] will produce= [tex]\frac{44.8}{67.2}\times 24.5=16.3L[/tex] of [tex]NH_3[/tex] at STP
Thus 16.3 L of ammonia gas can be formed from 24.5 L of hydrogen gas at STP
If the volume of a gas is 1020 ml at 120°C and 1160 torr, what will the volume be at 20°C and 700 torr?
Answer:
1260 mL
Explanation:
Use formula (P1V1)/T1 = (P2V2)/T2
convert C to K
120 +273 = 393 K
20 + 273 = 293 K
plug numbers in
((1160)(1020))/ 393 = ((V2)(700))/ 293
solve for V2
V2 = 1260.187 mL
1. Write the chemical symbol for each of the following elements.
Aluminum
Beryllium
Calcium
Flourine
Neon
Nitrogen
Silicon
Silfur
2. Write the name of the element for each of the following symbols.
Ar
B
Li
Na
Fe
3. What is the atomic number for the following elements?
C
Fe
Pb
O
N
Zn
Answer:
Chemical symbol:
Aluminum:Al
Berylium: Be
Calcium: Ca
Flourine: F
Neon: Ne
Nitrogen: N
Silicon: Si
Silfur: S
Element name
Ar: Argon
B: Boron
Li: Lithium
Na: Sodium
Fe: Iron
Atomic number
C:6
Fe: 26
Pb: 82
O: 8
N: 7
Zn: 30
Answer:
aluminum- Al
beryllium- Be
calcium- Ca
flourine- F
neon- Ne
nitrogen- N
silicon- Si
sulfur- S
_____________________________________________________
Ar- argon
B- boron
Li- lithium
Na- sodium
Fe- iron
______________________________________________________
C- 6
Fe- 26
Pb- 82
O- 8
N- 7
Zn- 30
Explanation:
What are the mole ratios of the following chemical equation: C3H8 + 5O2 --> 3CO2 + 4H2O?
Answer:Redox and combustion.
Explanation:
C3H8) reacts with oxygen in the air, so C3H8(g) + 5O2(g) = 3CO2(g) + 4H2O(g) Classification: Redox and combustion.
If a lab requires you to use 1.25 mol oxygen gas in a chemical reaction, how many molecules of oxygen will you need?
Answer:
7.53*10²³ molecules of oxygen will you need.
Explanation:
Avogadro's Number or Avogadro's Constant is called the number of particles that make up a substance (usually atoms or molecules) that can be found in the amount of one mole of said substance. Its value is 6.023*10²³ particles per mole. Avogadro's number applies to any substance.
You can then apply the following rule of three: if by definition of Avogadro's Number 1 mole of oxygen gas contains 6.023*10²³ molecules, 1.25 moles contains how many molecules?
[tex]amount of molecules=\frac{1.25 moles*6.023*10^{23}molecules }{1 mole}[/tex]
amount of molecules= 7.53*10²³
7.53*10²³ molecules of oxygen will you need.
This worm infects humans by getting into the blood stream. It gets a
warm, safe home in the blood stream. Humans are harmed because they
may go blind or have other complications due to the parasite.
A. Mutualism
B. Commensalism
C. Parasitism
Please help me find the correct answer, thank you.
Answer:
The third line
Explanation:
The first one us wrong because they're not all found inside,electron is outside.
The second one is wrong as I explained previously.
Lastly the fourth line is wrong because protons are found in the nucleus.
A sample of 1.00 moles of oxygen at 50°C and 98.6 kPa, occupies what volume?
Answer:
27.22 dm³
Explanation:
Given parameters:
number of moles = 1 mole
temperature= 50°C, in K gives 50+ 273 = 323K
Pressure= 98.6kpa in ATM, gives 0.973 ATM
Solution:
Since the unknown is the volume of gas, applying the ideal gas law will be appropriate in solving this problem.
The ideal gas law is mathematically expressed as,
Pv=nRT
where P is the pressure of the gas
V is the volume
n is the number of moles
R is the gas constant
T is the temperature
Input the parameters and solve for V,
0.973 x V = 1 x 0.082 x 323
V= 27.22 dm³
Two hydrogen atoms covalently bond to form a hydrogen molecule.
What is true about the hydrogen molecule?
A-The hydrogen molecule can have more or less energy than the hydrogen atoms.
B-The hydrogen molecule has less energy than the two atoms.
C-The hydrogen molecule has the same energy as the two atoms.
Answer:
B
Explanation:
the energy of two separate hydrogen atoms decreases as they approach each other, and the single electrons on each atom are shared to form a covalent bond.
Use the kinetic energy equation to explain why speed has a greater impact on kinetic energy than mass.
Answer: Hopefully this helps! sorry if not. :))
Speed has a greater impact on mass because its increases in velocity have an exponentially greater impact on translational kinetic energy because kinetic energy is proportional to velocity squared. Doubling an object's mass would only double its kinetic energy, however doubling its momentum would quadruple its velocity.
Organisms with their genetic material in a nucleus include A. Plants B. Animals C. All of these D. Fungi
Answer:
I believe it is 3. All of these.
Explanation:
Not all organisms hold their genetic code (DNA) inside a nucleus. In fact, some organisms don't have a nucleus at all but I'm pretty sure that these three do. I would select all of these.
Hope that helps and have a nice day.
A container has a volume of 5.85 L and a pressure of 4.25 atm. What will the volume be
If the containers pressure is changed to 2.75 atm?
Answer:
9.04 LExplanation:
The new volume can be found by using the formula for Boyle's law which is
[tex]P_1V_1 = P_2V_2[/tex]
Since we're finding the new volume
[tex]V_2 = \frac{P_1V_1}{P_2} \\[/tex]
We have
[tex]V_2 = \frac{4.25 \times 5.85}{2.75} = \frac{24.8625}{2.75} \\ = 9.0409...[/tex]
We have the final answer as
9.04 LHope this helps you
Which of the following is an example of a population having variations?
Some worms are nocturnal and some a diurnal
All polar bears have coats
Ostriches run fast
The rabbits that eat grass will survive
Answer:
Some worms are nocturnal and some a diurnal
Explanation:
Variation is difference between cells, individual organisms, or groups of organisms of any species caused either by genetic differences (genotypic variation) or by the effect of environmental factors on the expression of the genetic potentials (phenotypic variation).
NOTE:these are of the same species.
Which would easily give up more electrons during bonding?
Summer happens in Vermont when the sun's rays hit it less or more directly than any other time of year .
Answer:
More directly.
Explanation:
Summer happens in Vermont when the sun's rays hit it more directly than any other time of year because this direct angle causes more warm environment. In the winter season, the angle of sun is about 45° due to which the place receives less solar radiation and the environment is cold while on the other hand, in the summer season the angle of the sun is about 90° due to which direct sunlight occurs on the region that causes warm and hot environment.
The speed of sound in water is 350m/s. If a sound wave has the frequency of 50Hz.
What would the wavelength of the wave be?
Answer:
Explanation
Let, Wavelength = W,
Given, frequency (f) = 50 Hz, wave velocity (V) = 342 m/s
We know, V = f × W
=> 342 = 50 × W
=> W = 342/50 metre
=> W = 6.84 metre
Which statement best explains how the conditions identified in Part A affect the availability of opal?
A
Weathering processes no longer occur in Australia, so no new opal is formed.
B
Gems do not need an exact combination of elements or minerals to form, so opal forms more easily.
C
Opal formation occurs over large periods of time, so the number of opal deposits is limited.
D
Volcanoes in Australia no longer provide high temperatures and pressures, so no new opal is formed.
Answer:
C
Explanation:
If a reaction releases 675,000 Joules, how many kcal does it release?
Answer: If a reaction releases 675,000 Joules then it means it releases 161.328872 kcal.
Explanation:
According to the standard conversion,
[tex]1 Joule = 0.000239006 kcal[/tex]
Therefore, 675,000 Joules will be converted into kcal as follows.
[tex]1 Joule = 0.000239006 kcal\\675,000 J = 675000 J \times \frac{0.000239006 kcal}{1 J}\\= 161.328872 kcal[/tex]
Thus, we can conclude that if a reaction releases 675,000 Joules then it means it releases 161.328872 kcal.
What is the SI unit of length
4 points
Foot
Mile
Meter
Kilometer
Answer:
Answer is meter. ~~~~~~
Please answer this two questions as fast as you can
Explanation:
new Mexico and Louisiana
Answer: two two
Explanation:
Which pair of elements is in the same period? (Check ALL that apply) *
17 points
G
F
D
R
J
Answer:
D and R are in the same period
Explanation:
remember groups are vertical and periods are horizontal!
What molecules are affected by injury to the pancreas?
Answer:
Causative/sensitizing factors of pancreatic injury include refluxed bile acids, alcohol, and pH. They largely mediate downstream events such as elevated intracellular Ca2+ via influx through TRPC3 channels and release from IP3 and ryanodine-sensitive Ca2+ stores.
Explanation:
1.A sample of gas in a closed container occupies 250. mL at 1.25 atm of pressure. If the pressure increases to 2.00 atm while the temperature stays the same, what is the new volume in mL?
2.A sample of gas is held inside a flexible container where pressure is kept constant. At room temperature (21.1ºC), the container has a volume of 1.50 L. What is the volume of the gas if the container is placed in a deep freezer at -10.0ºC?
3.A sample gas is held inside a rigid container with a pressure of 50. kPa and a temperature of 290 K. What is the new temperature of the gas if the pressure is doubled?
Answer:
Una cantidad de gas ocupa un volumen de 80 cm3
a una presión de 750 mm Hg. ¿Qué volumen
ocupará a una presión de 1,2 atm.si la temperatura no cambia?
Explanation:
El volumen inicial de una cierta cantidad de gas es de 200 cm3
a la temperatura de 20ºC. Calcula el
volumen a 90ºC si la presión permanece constante.
How many liters at STP are in 8.0 x 102 grams of sulfur dioxide?
Answer:
280 liters at STP are in 8.0*10² grams of sulfur dioxide.
Explanation:
The STP conditions refer to the standard temperature and pressure. Pressure values at 1 atmosphere and temperature at 0 ° C are used and are reference values for gases. And in these conditions 1 mole of any gas occupies an approximate volume of 22.4 liters.
In this case, the molar mass of sulfur dioxide, that is, the mass of one mole of the substance, is 64 g/mole.
You can apply the following rule of three: if by definition of molar mass 64 grams of sulfur dioxide are contained in 1 mole, 8.0*10² grams are contained in how many moles?
[tex]amount of moles=\frac{8*10^{2}grams*1 mole }{64 grams}[/tex]
amount of moles= 12.5 moles
Now you can apply a new rule of three: if by STP conditions 1 mole of any gas occupies a volume of 22.4 liters, 12.5 moles will occupy how much volume?
[tex]volume=\frac{12.5 moles*22.4 L}{1 mole}[/tex]
volume= 280 L
280 liters at STP are in 8.0*10² grams of sulfur dioxide.
what Is The Use Of Sulpurdioxide
Sulfur dioxide is used as a food preservative, disinfectant, etc.
What is the volume, in liters, of 2.75 grams of fluorine gas at 35.0°C and 4.55 atm pressure?
The volume (in litres) of 2.75 g of fluorine gas at 35 °C and 4.55 atm is 0.402 L
How to determine the mole of fluorine gasMass of F₂ = 2.75 gMolar mass of F₂ = 2 × 19 = 38 g/mol Mole of F₂ =?
Mole = mass / molar mass
Mole of F₂ = 2.75 / 38
Mole of F₂ = 0.0724 mole
How to determine the volume Temperature (T) = 35 °C = 35 + 273 = 308 KPressure (P) = 4.55 atmGas constant (R) = 0.0821 atm.L/Kmol Number of mole (n) = 0.0724 moleVolume (V) =?Using the ideal gas equation, the volume of the gas can be obtained as follow:
PV = nRT
Divide both side by P
V = nRT / P
V = ( 0.0724 × 0.0821 × 308) / 4.55
V = 0.402 L
Learn more about ideal gas equation:
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