Answer:
A
Explanation:
Answer:
C
Explanation:
Pretty sure!
Which best describes the total mass of substances before and after a
combustion reaction?
A. The mass is the same because atoms are not created or
destroyed.
B. The mass is greater after the reaction because the number of
atoms increases.
C. The mass is the same because the molecules do not change.
D. The mass is less after the reaction because gases are produced.
Answer:
B. The mass is greater after the reaction because the number of
atoms increases.
What answer is it and how ? please help !!!!!! ill mark brainlyest if right
Answer:
The answer is B
Brainliest please!
A balloon is inflated with 1.25 L of helium at a temperature of 298K. What is
the volume of the balloon when the temperature is 310K?
Answer:
What is
the volume of the balloon when the temperature is 310K?
The titration of HCl with NaOH is an example of:
A. a weak acid-weak base titration,
B. a weak acid-strong base titration.
c. a strong acid-strong base titration.
D. a strong acid-weak base titration.
Answer:
I’m pretty sure it’s C
Explanation:
AP Ex
can someone answer this
how many moles of solute are needed to make 250 mL of a 0.50 M solution of sodium phosphate
Answer:
0.125 moles of solute
Explanation:
The formula for molarity (M) is moles of solute/liters of solution. First, convert 250 mL into liters:
250 mL/1 * 1 L/1000 mL = 0.25 L.
Then, plug in the values of m/L = M
m/0.25 = 0.5
Solve for moles (m). You would multiply 0.5 by 0.25.
m = 0.125
Lastly, if you'd like to check it and see if it's correct, do 0.125/0.25, and you should get 0.5 M.
Answer:
[tex]\boxed {\boxed {\sf 0.125 \ mol }}[/tex]
Explanation:
Molarity is a measure of concentration. It is the moles of solute per liters of solution.
[tex]molarity = \frac{ moles \ of \ solute}{ liters \ of \ solution}[/tex]
We know the solution has a molarity of 0.5 M or moles per liter. There are 250 milliliters of solution. First, we need to convert to liters. 1 liter is equal to 1000 milliliters.
[tex]\frac {1 \ L}{ 1000 \ mL}[/tex][tex]250 \ mL *\frac {1 \ L}{ 1000 \ mL}[/tex][tex]\frac {250 }{ 1000 } \ L = 0.25 \ L[/tex]Now we can substitute the values we know into the formula.
molarity= 0.5 mol/L liters of solution = 0.25 Lmoles of solute=x (unknown)[tex]0.5 \ mol/L= \frac{ x}{0.25 \ L}[/tex]
Since we are solving for the moles of solute, we need to isolate the variable x. It is being divided by 0.25 L. The inverse of division is multiplication. Multiply both sides by 0.25 L.
[tex]0.25 \ L *0.5 \ mol/L= \frac{ x}{0.25 \ L}*0.25 \ L[/tex]
[tex]0.25 \ L * 0.5 \ mol/L =x[/tex]
[tex]0.25 * 0.5 \ mol=x[/tex]
[tex]0.125 \ mol =x[/tex]
0.125 moles of sodium phosphate are needed to make 250 mL of a 0.50 M solution.
PLEASE HELP!! NO LINKS PLEASE REAL ANSWER!!!!!
What will be volume of 20.0 g of CH4 gas at a pressure of 0.950 atm and temperature of 21.0 oc?Question 1 options:
A. 21.8 L
B. 31.8 L
C. 2.27 L
D. 4.27 L
Jim makes a mixture which contains 10 mg of salt, 30 mg of sand, and some iron filings. The total mass of the mixture is 100 mg
Which amount of iron filings does Jim use in the mixture?
A10
B30
C40
D60
Answer:
Amount of iron fillings in mixture = 60 mg
Explanation:
Given:
Total mass of mixture = 100 mg
Amount of salt in mixture = 10 mg
Amount of sand in mixture = 30 mg
Find:
Amount of iron fillings in mixture
Computation:
Using Law of Conservation of mass;
Total mass of mixture = Amount of salt in mixture + Amount of sand in mixture + Amount of iron fillings in mixture
100 = 10 + 30 + Amount of iron fillings in mixture
100 = 40 + Amount of iron fillings in mixture
Amount of iron fillings in mixture = 100 - 40
Amount of iron fillings in mixture = 60 mg
A certain reaction has an activation energy of 51.02 kJ/mol. At what Kelvin temperature will the reaction proceed 4.50 times faster than it did at 365 K
Answer:
[tex]T_2=400.73K[/tex]
Explanation:
From the question we are told that:
Activation energy [tex]E_a= 51.02 kJ/mol.=>51.02*10^3J/mol[/tex]
Reaction Ratio [tex]\triangle K=4.50[/tex]
Initial Temperature [tex]T_1=365K[/tex]
Generally the equation for Final Temperature [tex]T_2[/tex] is mathematically given by
[tex]log \triangle K=\frac{E_a}{2.303R}*(\frac{T_2-T_1}{T_1T_2})[/tex]
Where
[tex]R=Gas constant[/tex]
[tex]R =8.3143[/tex]
Therefore
[tex]log 4.50=\frac{51.2*10^3}{2.303*8.31432}*(\frac{T_2-365}{365*T_2})[/tex]
[tex]log 4.50=7.328*\frac{T_2-365}{T_2}[/tex]
[tex]0.0892=\frac{T_2-365}{T_2}[/tex]
[tex]0.0892T_2=T_2-365[/tex]
[tex]365=T_2-0.0892T_2[/tex]
[tex]365=0.91T_2[/tex]
[tex]T_2=\frac{365}{0.91}[/tex]
[tex]T_2=400.73K[/tex]
2C4H10(g) + 1302(g) → 8CO2(g) + 10 H2O(g)
3. How many moles of water is produced from 0.859 moles of C4H10?
Answer:
Explanation:...
What volume is occupied by 2.0 mol of gas at 3.0 atm
and 27 °C?
A 500.0 g sample of aluminium, I initially at 25.0 degrees, absorbs heat from its surroundings and reaches a final temperature of 90.7 degrees. How much heat (in KJ) has been absorbed by the sample? To one decimal place
Specific heat= 0.9930j g-1 K-1 for aluminium
A 500.0 g sample of aluminum, initially at 25.0 degrees, absorbs heat from its surroundings and reaches a final temperature of 90.7 degrees. 32.62245 kJ heat has been absorbed by the sample.
What is specific heat?The term specific heat is defined as the amount of heat required to increase the temperature of 1 gram of a substance 1 degree Celsius (°C).
To calculate the amount of heat absorbed by the sample, use the formula:
Q = mcΔT
where Q is the amount of heat absorbed by the sample, m is the mass of the sample, c is the specific heat of aluminum, and ΔT is the change in temperature of the sample.
Substituting the given values into the formula, we get:
Q = 500.0 g × 0.9930 J/g·K × (90.7°C - 25.0°C)
Q = 500.0 g × 0.9930 J/g·K × 65.7 K
Q = 32,622.45 J
To convert the result to kilojoules (kJ), we divide by 1000:
Q = 32.62245 kJ
Thus, the amount of heat absorbed by the sample is 32.6 kJ.
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Calculate the specific heat of a substance given that 49 joules of heat is required to raise the temperature of 25.0 g of the substance from 92.6 ºC to 99.4 ºC.
Answer:
0.29 J/g.°C
Explanation:
Step 1: Given data
Added heat (Q): 49 JMass of the substance (m): 25.0 gInitial temperature: 92.6 °CFinal temperature: 99.4 °CStep 2: Calculate the temperature change (ΔT)
ΔT = 99.4 °C - 92.6 °C = 6.8 °C
Step 3: Calculate the specific heat of the substance (c)
We will use the following expression.
Q = c × m × ΔT
c = Q / m × ΔT
c = 49 J / 25.0 g × 6.8 °C = 0.29 J/g.°C
Read about reverse osmosis and multistage flash distillation .Then identify at least three advantages and three
disadvantages for each process
Answer:
Meaning, Advantages & Disadvantages of - Osmosis, Multiflash Distillatiob
Explanation:
Osmosis is movement of solvent (like water) through semi permeable membrane (like living cell) into solution of higher solute concentration.Advantages - It assists equalising concentration of solute on two sides of membrane. Reverse Osmosis is used for efficient water softening, it is easy to maintain.
Disadvantages - It needs a lot of energy. A lot of pressure is required for deionisation. Water acidity level increases, as minerals get deionised.
Multistage flash distillation refers to desalination water distilling seawater, by flashing water portions in steams in various stages of concurrent heat exchangers.Advantages - Its Cost efficient , distillation uses waste heat. It has High gain output ratio. Quality of feedwater is less significant, compared to reverse osmosis.
Disadvantages - It has high operating cost in case of waste heat unavailability. High temperature imply high corrosion & scale formation.
Ammonia will decompose into nitrogen and hydrogen at high temperature. An industrial chemist studying this reaction fills a 5.0L flask with 4.5 atm of ammonia gas, and when the mixture has come to equilibrium measures the amount of nitrogen gas to be 1.1 atm. Calculate the pressure equilibrium constant for the decomposition of ammonia at the final temperature of the mixture. Round your answer to 2 significant digits.
Answer:
Kp = 7.4727
Explanation:
Let's write the balanced equilibrium reaction:
2NH₃ <-------> N₂ + 3H₂ Kp = ??
Now, if we want to calculate the Kp, we need to write an ICE chart with this reaction, which is the following:
2NH₃ <-------> N₂ + 3H₂
I. 4,5 0 0
C. -2x +x +3x
E. 4,5-2x x 3x
According to this chart, the Kp expression should be:
Kp = (PH₂)³ * (PN₂) / (PNH₃)² (1)
The value of x, we already know it because the problem states that the amount of nitrogen gas is 1.1 atm, so replacing this value into (1) we have:
Kp = (3*1.1)³ * (1.1) / (4.5 - (2 * 1.1))²
Kp = 39.5307 / 5.29
Kp = 7.4727Hope this helps
The substance ammonia has the following properties: normal melting point: 195.4 K normal boiling point: 239.8 K triple point: 5.9×10-2 atm, 195.3 K critical point: 111.5 atm, 405.5 K At temperatures above 405.5 K and pressures above 111.5 atm, NH3 is a _________ . NH3 does not exist as a liquid at pressures below atm. NH3 is a _________ at 5.90×10-2 atm and 249.5 K. NH3 is a _________ at 1.00 atm and 236.0 K. NH3 is a _________ at 24.6 atm and 185.6 K.
Answer:
a) Superficial fluid
b) 5.9*10^-2 atm
c) Gas
d) Liquid
e) Solid
Explanation:
a) At temperatures above 405.5 K and pressures above 111.5 atm, NH3 is a superficial fluid because liquid and gases does not exit at temperature and pressure greater than 405.5 K and 111.5 atm
b) NH3 does not exist as a liquid at pressures below 5.9*10^-2 atm , That is below the triple point there is existence of liquid
c) NH3 is a Gas at 5.90×10^-2 atm and 249.5 K.
d) NH3 is a Liquid at 1.00 atm and 236.0 K. because pressure and temperature ( standard ) is between the given normal melting and boiling point
e) NH3 is a solid at 24.6 atm and 185.6 K . because the pressure here is more than that of triple point while the temperature is lesser
What is the initial and final mass of the zinc and copper?
Answer:the final mass of copper is 3.84 g. There was an increase in mass of 1.84 g from the initial mass of 2.0 g.
Explanation:
What is the mass of 9.23*10^41 atoms of phosphorus (P)?
(Put your answer in scientific notation)
Answer:
[tex]m_P=4.75x10^{19}g\ P[/tex]
Explanation:
Hello there!
In this case, according to the given atoms of phosphorous, it is possible to calculate the mass of those atoms by bearing to mind the definition of mole in terms of the Avogadro's number; which refers to the mass and amount of particles in one mole of any element as equal to the atomic mass and the Avogadro's number respectively:
[tex]1 molP=6.022x10^{23}atoms\ P=30.97gP[/tex]
Which is used to obtain the required mass of P:
[tex]m_P=9.23x10^{41}atoms\ P*\frac{30.97g P}{6.022x10^{23}atoms\ P}\\\\m_P=4.75x10^{19}g\ P[/tex]
Regards!
A helium-filled balloon contains 0.16 mol He at 101 kPa and a temperature of 23°C. What is
the volume of the gas in the balloon?
V = 3.9 L
Explanation:
Given:
T = 23°C + 273 = 296K
n = 0.16 mol He
P = 101 kPa = 0.997 atm
R = universal gas constant = 0.08205 L-atm/mol-K
V = ?
Using the ideal gas law,
PV = nRT
V = nRT/P
= (0.16 mil He)(0.08205 L-atm/mol-K)(296K)/(0.997 atm)
= 3.9 L
2+4 help please i will fail 6th grade
Answer:
6
Explanation:
lol
how much corn syrup should be added to water to make 200 mL of a 10% by volume solution
To make 200 mL of a 10% by volume solution, add 20 mL corn syrup to water.
What is volume solution?Volume percent of a solution is defined as the ratio of the volume of solute present in a solution to the volume of the solution as a whole. It means that the volume of a closed figure determines how much three-dimensional space it can occupy. In terms of numerical value, volume is the amount of three-dimensional space enclosed by a closed surface. For example, a substance's space can be solid, liquid, gas, or plasma, or any other space-occupying shape. The volume percentage of a solution can be calculated by dividing the volume of solute by the volume of solution and multiplying the result by 100. The basic formula for volume is length width height, whereas the basic formula for area of a rectangular shape is length width height. The calculation is unaffected by how you refer to the various dimensions: you can, for example, use 'depth' instead of 'height.'To learn more about volume solution, refer to:
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determine the maximum amount of NaN03 that was produced during the experiment. Explain how you determined the amount
Answer:
9 moles of NaNO3 is obtained
Explanation:
The balanced chemical reaction equation for the reaction is;
Al(NO3)3 + 3NaCl-------> 3NaNO3 + AlCl3
Now, we have to determine the limiting reactant. The limiting reactant yields the least amount of NaNO3.
1 mole of Al(NO3)3 yields 3 moles of NaNO3
4 moles of Al(NO3)3 yields 4 * 3/1 = 12 moles of NaNO3
Also,
3 moles of NaCl yields 3 moles of NaNO3
9 moles of NaCl yields 9 * 3/3 = 9 moles of NaNO3
Hence, NaCl is the limiting reactant and 9 moles of NaNO3 is obtained.
9 moles of NaNO₃ is obtained.
Balanced chemical reaction:
[tex]Al(NO_3)_3 + 3NaCl-----> 3NaNO_3 + AlCl_3[/tex]
From the reaction, it is seen that the limiting reactant yields the least amount of NaNO₃.
1 mole of Al(NO₃)₃ yields 3 moles of NaNO₃
4 moles of Al(NO₃)₃ yields 4 * 3/1 = 12 moles of NaNO₃
Also,
3 moles of NaCl yields 3 moles of NaNO₃
9 moles of NaCl yields 9 * 3/3 = 9 moles of NaNO₃
Hence, NaCl is the limiting reactant and 9 moles of NaNO₃ is obtained.
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On the basis of the information above, what is the approximate percent ionization of HNO2 in a 1.0 M HNO2 (aq) solution?
Answer:
The answer is "2%"
Explanation:
Equation:
[tex]HNO_2\ (aq) \leftrightharpoons H^{+} \ (aq) + NO_2^{-}\ (aq) \\\\\ K_a = 4.0\times \ 10^{-4}[/tex]
[tex]H^{+}=?[/tex]
Formula:
[tex]Ka = \frac{[H^{+}][NO_2^{-}]}{[HNO_2]}[/tex]
Let
[tex][H^{+}] = [NO_2^{-}] = x[/tex] at equilibrium
[tex]x^2 = (4.0\times 10^{-4})\times 1.0\\\\x = ((4.0\times 10^{-4})\times 1.0)^{0.5} = 2.0 \times 10^{-2} \ M\\\\[/tex]
therefore,
[tex][H^{+}] = 2.0\times 10^{-2} \ M = 0.02 \ M[/tex]
Calculating the % ionization:
[tex]= \frac{([H^{+}]}{[HNO_2])} \times 100 \\\\= \frac{0.02}{1}\times 100 \\\\= 2\%\\\\[/tex]
The approximate percent ionization of HNO₂ in a 1.0 M HNO₂ (aq) solution is 2%.
How we calculate the % ionization?% ionization of any compound will be calculated as follow:
% ionization = ([ion]/[acid or base]) ₓ 100
Given chemical reaction with ICE table will be represented as:
HNO₂(aq) → H⁺(aq) + NO₂⁻(aq)
initial 1 0 0
change -x +x +x
equilibrium 1-x x x
Equilibrium constant will be represented as:
Ka = [H⁺][NO₂⁻] / [HNO₂]
Acid dissociation constant for HNO₂ = 4×10⁻⁴
Putting all values in the above equation, we get
4×10⁻⁴ = x² / 1-x
Value of changeable quantity is very less, so we neglect from the concentration of HNO₂.
4×10⁻⁴ = x²
x = 2 × 10⁻²
So, the concentration of H⁺ ion = 2 × 10⁻²M
Now we put all these values in the % ionization equation, we get
% ionization = (0.02/1) × 100 = 2%
Hence , % ionization is 2%.
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Se prepara una concentración molar 0.5M de hidróxido de sodio (NaCH) con la finalidad de determinar el grado de acidez de una bebida embotellada. Calcula la cantidad de gramos de hidróxido de sodio (NaCH) que se requiere para preparar 5 litros de dicha solución.
Answer:
100 g
Explanation:
Primero hay que calcular el número requerido de moles de NaOH, usando la definición de molaridad:
Molaridad = moles / litros0.5 M = moles / 5 Lmoles = 2.5 molesAhora hay que convertir 2.5 moles de NaOH en gramos, usando su masa molecular:
2.5 mol * 40 g/mol = 100 gSe requieren 100 gramos de NaOH.
To obtain pure lead, lead (II) sulfide is burned in an atmosphere of pure oxygen. The products of the reaction are lead and sulfur trioxide (SO3). Write a balanced chemical equation for this process. How many grams of lead will be produced if 2.54 grams of PbS is burned with 1.88 g of O2? Express your answer to the correct number of significant figures. Be sure to show all steps completed to arrive at the answer. (Hint: be sure to work the problem with both PbS and O2).
Answer: 2.20 g Pb
They gave us the masses of two reactants and asked us to determine the mass of the product. We will need a chemical equation with masses and molar masses, so, let's gather all the information in one place.
Mᵣ: 239.27 32.00 207.2
2PbS + 3O₂ ⟶ 2Pb + 2SO₃
m/g: 2.54 1.88