melting of wax is a physical reaction, because the same amount of wax exists before and after the change.
physical reaction is a change from one state (solid or liquid or gas) to another without a changing in the chemical composition.It alters the form, shape or appearance of a material but does not convert the material into a new substance. examples Freezing Water, Sanding a piece of paper, Bending a paper clip, Mixing oil and vinegar etc both physical and chemical changes obey the law of conservation . It also entails that the mass of a substance present before a reaction should be equal to the mass obtained after the reaction.To know more about physical reaction visit :
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Bohr's model was correct in assigning energy levels to electrons.
Answer:
yes that is true........
How many hybrid orbitals are found in CCl4? o one o two o three o four
Answer:
I Believe it is 4 orbitals s,p,p,p or aka sp^3
Explanation:
Answer:
Four because its hybridization is SP3 which means one s and three p orbitals combine to form hybrid orbitals
Explanation:
consider a block G with mass of 49.231 g and a volume of 23.8 ml what is its density
Answer:
ρ = 2.07 g/mL
Explanation:
Step 1: Given data
Mass of the block G (m): 49.231 gVolume of the block G (V): 23.8 mLStep 2: Calculate the density (ρ) of the block G
The density is an intrinsic property, equal to the mass of the block divided by its volume.
ρ = m/V
ρ = 49.231 g/23.8 mL
ρ = 2.07 g/mL
The density of the block G is 2.07 g/mL.
How many neutrons does this atom have?
04
O 6
O 10
O 14
plzzzz i need help i will give 50 points
Answer:
c maybe if right plz mark brainliest
Explanation:
Answer:
14
Explanation:
it 14 there are 14 neutrons
Hydrogen gas H2 is the least dense of all gases. A sample of H2 gas is found to occupy a volume of 1.23 L at 755 mmHg and 0 ◦C. What volume , in liters, will this same gas occupy at .97 atm and a temperature of 50 ◦C.(10 points)
Please include equation used, variable you solved for and answer with correct units
Answer:
V₂ = 1.48 L
Explanation:
Given data:
Initial volume = 1.23 L
Initial pressure = 755 mmHg (755/760 =0.99 atm)
Initial temperature = 0 °C (0 +273 = 273 K)
Final temperature = 50°C (50+273 = 323 K)
Final volume = ?
Final pressure = 0.97 atm
Formula:
P₁V₁/T₁ = P₂V₂/T₂
P₁ = Initial pressure
V₁ = Initial volume
T₁ = Initial temperature
P₂ = Final pressure
V₂ = Final volume
T₂ = Final temperature
Solution:
V₂ = P₁V₁ T₂/ T₁ P₂
V₂ = 0.99 atm × 1.23 L × 323 K / 273 K × 0.97 atm
V₂ = 393.32 atm .L. K / 264.81 atm.K
V₂ = 1.48 L
If you have a gold coin that contains 0.637 moles of gold, how many grams of gold does it contain?
What type of materials are attracted to a magnet?
Answer:
Magnets are only attracted to special metals. Iron, cobalt and nickel are magnetic. Metals that have iron in them attract magnets well. Steel is one.
Explanation:
What type of chemical reaction is the following? 2 Fe + O2
Single replacement
Double replacement
Decomposition
Synthesis
O Combustion
Answer:
Synthesis
Explanation:
When glucose is oxidized the product is
Select one:
O a. gluconic acid
b. sucrose
c. galactose
d. glucitol
O e. maltose
Answer:
the answer is C galactose
Answer:
a. gluconic acid
Explanation:
According to kinetic theory, which two factors are important for a successful
reaction to occur?
A. Collisions between particles with the right orientation
B. Collisions between particles with sufficient energy
C. Collisions between particles with the right concentrations
D. Collisions between particles with sufficient mass
The two factors for a successful reaction to occur are collisions between particles with the right orientation and sufficient energy (A and B).
What is the kinetic theory?The kinetic theory is a model explaining the movement (motion) of particles in a given substance.
This theory (kinetic theory) is used to explain the thermodynamic features of gaseous particles.In conclusion, the two factors for a successful reaction to occur are collisions between particles with the right orientation and sufficient energy (A and B).
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Which part of the cell is a gel-like material that contains chemicals used to break down large molecules so that they can be used by other organelles?
Cytoplasm
Mitochondrion
Nucleus
Ribosome
A. Cytoplasm is the correct answer!
my brain hurts. halp
Answer:
the answer is C ( i hope your teacher explains
The Al2O3 crystal structure (corundum) consists of an HCP arrangement of O2- ions; the Al3 ions occupy octahedral positions. What fraction of the available octahedral positions are filled with Al3 ions
Answer:
2/3
Explanation:
Crystals structures can also be seen when two elements combines together and the perfect example is Al₂O₃ which is given in the question above. Just like it is given in the question above, the kind of arrangement in the crystal structure for Al₂O₃ is called HCP which stands for Hexagonally Closed Pack.
The aluminum ions which is in form of Al³⁺ occupies the two-third[2/3] positions while the position that the oxygen ion occupies is one[1].
what is the mass of 0.82 mol of the element potassium (K)? answer in units of g.
molar mass of potassium is 39.0983 g/Mol
using conversion factors
0.82 Mol K (39.0983 g/ 1 mol)
mol cancels out, leaves you w grams
answer: 32.1 grams K
1. Define the units for molarity. Page |152 Exp. 14 pH and Solutions Pre Lab Questions (1 of 1) 2. A solution contains 5.25 grams of sodium chloride in 750.0 mL of solution. Determine the molarity of the solution. Na
Answer:
1. mol/L
2. 0.120 M
Explanation:
1. Molarity is equal to the moles of solute divided by the liters of solution. The units of molarity are mol/L.
2.
Step 1: Given data
Mass of sodium chloride (solute): 5.25 gVolume of solution (V): 750.0 mL = 0.7500 LStep 2: Calculate the moles of solute (n)
The molar mass of NaCl is 58.44 g/mol.
n = 5.25 g × 1 mol/58.44 g = 0.0898 mol
Step 3: Determine the molarity of the solution
We will use the definition of molarity
M = n/V
M = 0.0898 mol / 0.7500 L = 0.120 M
Liquid hexane CH3CH24CH3 will react with gaseous oxygen O2 to produce gaseous carbon dioxide CO2 and gaseous water H2O
Suppose 0.862 g of hexane is mixed with 5.1 g of oxygen. Calculate the maximum mass of carbon dioxide that could be produced by the chemical reaction. Be sure your answer has the correct number of significant digits.
Answer:
2.64g of CO₂ are produced
Explanation:
The reaction of hexane with O₂ is:
C₆H₁₄ + 19/2O₂ → 6CO₂ + 7H₂O
To solve this question, we must convert each mass of reactant to moles in order to find limiting reactant and, with the chemical reaction we can find the moles of carbon dioxide produced and the maximum mass produced:
Moles hexane -Molar mass: 86.18g/mol-:
0.862g * (1mol / 86.18g) = 0.01 moles
Moles Oxygen -Molar mass: 32g/mol-:
5.1g * (1mol / 32g) = 0.16 moles
For a complete reaction of 0.01 moles of hexane there are required:
0.01moles hexane * (19/2 Oxygen / 1mol Hexane) = 0.095 moles oxygen
As there are 0.16moles, limiting reactant is hexane.
0.01 moles of hexane produce:
0.01 moles * (6 moles carbon dioxide / 1 mole hexane) = 0.06 moles of CO₂.
The mass is -Molar mass CO₂: 44g/mol-:
0.06 moles of CO₂ * (44g/mol) =
2.64g of CO₂ are producedBROOO PLEASE HELP ME
Answer:
Flask d
Explanation:
I promise u it’s flask d
Select the correct answer.
Which particles make up the nucleus of an atom?
A.
protons and electrons
B
neutrons and electrons
с.
protons only
D
protons and neutrons
E.
neutrons only
Using the van der waals equation, the pressure in a 22.4 L vessel containing 1.50 mol of chlorine gas at 0.00 c is____________atm. (a= 6.49L^2-atm/mol^2, b=0.0562 L/mol)
A. 1.50
b. 0.676
c. 0.993
d. 1.48
e. 1.91
Answer:
D. 1.48atm
Explanation:
Van der waals equation is given as:
(P +an²/v²) (v - nb) = nRT
Where;
P = pressure (atm)
V = volume (L)
R = gas constant (0.0821 Latm/molK)
a and b = gas constant specific to each gas
T = temperature (K)
n = number of moles
According to the given information; V = 22.4L, T = 0.00°C (273.15K), R = 0.0821 Latm/molK, a = 6.49L^2-atm/mol^2, b = 0.0562 L/mol, n = 1.5mol
Hence;
(P + 6.49 × 1.5²/22.4²) (22.4 - 1.5×0.0562) = 1.5 × 0.0821 × 273.15
(P + 6.49 × 2.25/501.76) (22.4 - 0.0843) = 33.638
(P + 0.0291) (22.316) = 33.638
22.316P + 0.649 = 33.638
22.316P = 33.638 - 0.649
22.316P = 32.989
P = 32.989/22.316
P = 1.478
P = 1.48atm
Metals are what proportion of the periodic table? *
1/4
2/3
1/2
3/4
Question 15 (1 point)
When a toy car is wound up and released on a tile floor, It accelerates as shown in the diagram. What is the force in Newtons that the car's
wheels exert on the floor when it is released?
Acceleration = 0.5 m/s2
Mass = 1.0 kg
Оа
Ob
Ос
Od
0.05N
0.5 N
SN
50 N
Answer:
Option B. 0.5 N.
Explanation:
Data obtained from the question include:
Mass (m) = 1 Kg
Acceleration (a) = 0.5 m/s²
Force (F) =?
Force is defined as the product of mass (m) and acceleration (a). Mathematically, it is expressed as:
Force (F) = mass (m) × acceleration (a)
F = ma
Using the above equation, we can obtain the force exerted on the floor as follow:
Mass (m) = 1 Kg
Acceleration (a) = 0.5 m/s²
Force (F) =?
F = ma
F = 1 × 0.5
F = 0.5 N
Thus, the car exerted a force of 0.5 N on the floor.
How much water must be added to 15 ml of a 2.5 M solution of sodium chloride to make a 2.0 M solution of sodium chloride?
Answer:
3.75mL need to be added
Explanation:
M1 x V1 = M2 x V2
so V2=(M1xV1)/M2
(2.5Mx.015L)/2M= .01875L or 18.75ml
since we want to know how much needs to be added we subtract 18.75 from 15
Giving us 3.75ml need to be added
Scientific notation.
Answer:
23.1 x 10^11
Explanation:
(4.2x5.5) x (10^9x10^2)
23.1 x 10^11 (Add the exponents, and multiply the decimals.)
I hope this helped! :)
PLEASE HELP!!! I'll give brainliest answer
Answer:
1. MG
2. N
3. F
4. NA
5. O
6. K
Answer:
Largest to Smallest: Na, K, Mg, N, O, F
Explanation:
Synthesis of cholesterol takes place in the
Oliver.
gall bladder
small intestine.
large intestine.
pancreas.
Calculate the pH of a titration at the point when 15.0 mL of 0.15 M NaOH is added to 30.0 mL 0f 0.20 M HNO.
Answer:
The correct answer is 1.10.
Explanation:
Based on the given information, the molarity of the NaOH is 0.15 M, that is, 0.15 moles per liter of the solution.
Now the moles present in the 15 ml of the solution will be,
0.015 × 0.15 = 2.25 × 10⁻³ moles of NaOH or 0.0025 moles of NaOH
Now, molarity of the HNO₃ given is 0.20 M, which means 0.2 moles per liter of the solution.
Now the moles present in the 30 ml of the solution will be,
0.030 × 0.2 = 0.006 moles of HNO₃
Now the complete disintegration of acid and base will be,
NaOH (aq) (0.025 moles) ⇔ Na⁺ (aq) (0.025) + OH⁻ (aq) (0.025 moles)
HNO₃ (aq) (0.006 moles) ⇔ H⁺ (0.006 moles) + NO₃⁻ (aq) (0.006 moles)
Now the additional Hydrogen ions at titration point is,
= 0.006 - 0.0025 = 0.0035 moles of H+
Now the concentration of H+ ions in the 45 ml of the solution will be,
= 0.0035/45 × 1000
= 0.078 M
pH = -log[H⁺] = -log [0.078]
= 1.10
How many grams are in 0.040 moles zirconium (Zr)?
Answer:
91.224 gram
Explanation:
Answer:
3.64896 grams Zr
Explanation:
Given: amount of moles of Zr: 0.040
Find: the amount of grams of Zr
1. Find molar mass of Zr
- after looking at the periodic table, you can tell it's 91.224 g/mol
2. Solve
([tex]\frac{0.040 mol Zr}{1}[/tex])( [tex]\frac{91.224 g Zr}{1 mol Zr}[/tex])
- the mol units get cancelled out, and you're left with 0.040 x 91.224 g
3. Multiply that out: 3.64896 grams of zirconium
How many atoms of O are there in 1.00 moles of CO2?
Answer:
1.204 x 10²⁴ atoms of oxygen in 1 mole of CO₂
Explanation:
1 mole of CO₂ contains 6.02 x 10²³ molecules of CO₂
1 molecule of CO₂ contains 2 atoms of oxygen
Therefore, Atoms of oxygen in 1 mole of CO2 => 6.02 x 10²³ molecules CO₂ x
2 atoms oxygen / molecule CO₂ = 2 X 6.02 X10²³ atoms of oxygen = 1.204x10²⁴ atoms of oxygen in 1 mole CO₂
3.124. X-ray Absorption Spectroscopy Electrons in multielectron
atoms absorb X-rays at characteristic energies, leading to
ionization. The characteristic energies for each element allow
scientists to identify the element. For magnesium, X-rays
with λ = 952 pm are required to selectively eject an electron
A
from the n = 1 energy level, and X-rays with λ = 197 nm
remove an electron from the n = 2 energy level.
a. Calculate the frequency and energy of those X-rays.
b. Why are the wavelengths and energies different for the
two electrons?
c. In terms of Bohr's values of n, what transitions do those
represent?
Answer:
ddddddddddddedewxdedww
Explanation:
ddddddddddddddddddddddd
why can an object with balanced forces still be in motion/
Answer:
Diagram A: Balanced Forces
These forces are balanced, so the motion of the object stays the same. The object in the diagram could be sitting still, or it could be moving. But its motion is not changing. This is because the forces acting on it from opposite sides are exactly the same size.
Explanation:
Answer:
Because a balanced force can keep an object moving at a constant velocity.
Explanation: