Answer:
Purple light.
Yellow light.
Explanation:
When a material gains thermal energy and melts, it is undergoing a physical change.
Answer:
True, it undergoes a physical change.
Explanation:
A physical change is a change that does not change the chemical makeup of a material. This includes altering its shape.
Ram has power of 550 watt.What does it mean?
Answer:
for electricity, watts as in back to the future "1.21 jigga watts"!
Explanation:
every spring has an equilibrium position which statement describe a spring at it equilibruim position?
A 12 gram piece of Cu at 475 oC is placed in contact with a 15 gram piece of Cr at 265 oC.
Assume the two pieces of metal are the system and that there is no heat exchange between system and surrounding.
What is the final temperature of the two pieces of metal expressed in degree C?
Answer:
349.22°C
Explanation:
Let the final temperature of the two pieces of metal be x.
Now, the warmer metal which is C u reduces from 475°C to x. Thus Δt for C u is; Δt1 = 475 - x.
The cooler metal Cr increases in temperature from 265°C to x. Thus, it's change in temperature is Δt for Cr is; Δt2 = x - 265.
Now from conservation of energy, the amount of energy leaving the C u metal is equal to the amount of energy entering the Cr metal.
Thus;
q_lost = q_gain
Where;
q_lost = m1•c1•Δt1
q_gained = m2•c2•Δt2
Now, c1 & c2 are the specific heat capacity of C u and Cr respectively.
From online tables, c1 = 0.385 J/g°C and c2 = 0.46 J/g°C
We are given;
m1 = 12g and m2 = 15g
Thus;
12 × 0.385 × (475 - x) = 15 × 0.46 × (x - 265)
2194.5 - 4.62x = 6.9x - 1828.5
6.9x + 4.62x = 2194.5 + 1828.5
11.52x = 4023
x = 4023/11.52
x = 349.22°C
Why does the flask have to be closed during the hydrochloric acid and sodium carbonate reaction?
Answer:
The flask has to be closed during the hydrochloric acid and sodium carbonate reaction as the resultant gas got trapped inside the closed flask.
Explanation:
The hydrochloric acid and sodium carbonate reaction was exothermic that caused the pressure to decrease. The flask has to be closed during the hydrochloric acid and sodium carbonate reaction as the resultant gas got trapped inside the closed flask.
In exothermic reactions, energy is produced in the form of heat or light.
A baseball has serval properties. Write one property that a baseball has.
complete sentences.
A Barometer reads 29.1 inches of mercury.Calculate this pressure in mmHg.
What is the answer?
This follows a simple conversion technique. Basically what the question is trying to say here is to convert 29.1 inHg to mmHg. 1 inHg is equal to 25.4 mmHg so 29.1 inHg would be equal to [tex]25.4 * 29.1[/tex] which when evaluated turns out to be: [tex]739.14[/tex]. :D
The pressure will be 739.14 mm Hg.
What is pressure?The SI unit measuring pressure would be the pascal, which measures the force of each unit area of the surface.
Calculation of pressure
It is known that 1inHg = 25.4 mm Hg.
Hence, the pressure = 25.4 × 29.1 = 739.14 mm Hg
Therefore, the pressure will be 739.14 mm Hg.
To know more about pressure
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in the following chemical reaction between H_2 and Cl_2 to produce HCl, what is the sum of the mass of HCl produced plus the mass of left over reactants when 0.40 g of H_2 completely reacts with 12.35 g of Cl_2?
H_2(g) + Cl_2(g) → 2HCl(g)
Answer:
Left over mass of hydrogen = 0.06 g
Mass of HCl produced = 12.41 g
Explanation:
Given data:
Mass of H₂ = 0.40 g
Mass of Cl₂ = 12.35 g
Mass of left over reactant = ?
Mass of HCl produced = ?
Solution:
Chemical equation:
H₂ + Cl₂ → 2HCl
Number of moles of H₂:
Number of moles = mass / molar mass
Number of moles = 0.40 g/ 2 g/mol
Number of moles = 0.2 mol
Number of moles of Cl₂:
Number of moles = mass / molar mass
Number of moles = 12.35 g/ 71 g/mol
Number of moles = 0.17 mol
Now we will compare the moles of HCl with H₂ and Cl₂.
H₂ : HCl
1 : 2
0.2 : 2×0.2 = 0.4
Cl₂ : HCl
1 : 2
0.17 : 2 × 0.17 = 0.34
Chlorine is limiting reactant.
Mass of HCl produced:
Mass = number of moles × molar mass
Mass = 0.34 mol × 36.5 g/mol
Mass = 12.41 g
Leftover mass of hydrogen:
Cl₂ : H₂
1 : 1
0.17 : 0.17
Number of moles of H₂ react with Cl₂ are 0.17.
Moles remain unreacted = 0.2 - 0.17 = 0.03 mol
Mass left over:
Mass = number of moles × molar mass
Mass = 0.03 mol × 2 g/mol
Mass = 0.06 g
The sum of the mass of HCl produced plus the mass of left over reactants is:
Mass of hydrogen = 0.06 g
Mass of HCl = 12.41 g
Chemical ReactionGiven:
Mass of H₂ = 0.40 g
Mass of Cl₂ = 12.35 g
Mass of left over reactant = ?
Mass of HCl produced = ?
Chemical equation: H₂ + Cl₂ → 2HClNumber of moles of H₂:
Number of moles = mass / molar mass
Number of moles = 0.40 g/ 2 g/mol
Number of moles = 0.2 mol
Number of moles of Cl₂:
Number of moles = mass / molar mass
Number of moles = 12.35 g/ 71 g/mol
Number of moles = 0.17 mol
The moles of HCl with H₂ and Cl₂.
H₂ : HCl
1 : 2
0.2 : 2×0.2 = 0.4
Cl₂ : HCl
1 : 2
0.17 : 2 × 0.17 = 0.34
The chlorine is limiting reactant.
Mass of HCl produced:
Mass = number of moles × molar mass
Mass = 0.34 mol × 36.5 g/mol
Mass = 12.41 g
Leftover mass of hydrogen:
Cl₂ : H₂
1 : 1
0.17 : 0.17
Number of moles of H₂ react with Cl₂ are 0.17.
Moles remain unreacted = 0.2 - 0.17 = 0.03 mol
Mass left over:
Mass = number of moles × molar massMass = 0.03 mol × 2 g/molMass = 0.06 gLearn more about "Moles":
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An excess of oxygen reacts with 451.4 g of lead, forming 374.7 g of lead(II) oxide. Calculate the percent yield of the reaction.
Answer: The percent yield of the reaction is 77.0 %
Explanation:
[tex]2Pb+O_2\rightarrow 2PbO[/tex]
[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}[/tex]
[tex]\text{Number of moles of lead}=\frac{451.4g}{207.2g/mol}=2.18moles[/tex]
[tex]\text{Number of moles of lead oxide}=\frac{374.7g}{223.2g/mol}=1.68moles[/tex]
According to stoichiometry:
2 moles of [tex]Pb[/tex] produces = 2 moles of [tex]PbO_2[/tex]
2.18 moles of [tex]Pb[/tex] is produced by=[tex]\frac{2}{2}\times 2.18=2.18moles[/tex] of [tex]PbO_2[/tex]
Mass of [tex]PbO_2[/tex] =[tex]moles\times {\text {Molar mass}}=2.18\times 223.2g/mol=486.6[/tex]
percent yield =[tex]\frac{374.7g}{486.6g}\times 100=77.0\%[/tex]
PLEASE HELP ME!!!!!!!!!!!!!!!!!!!
WRITE A SHORT PASSAGE ON HOW FIBRES ARE SPUN
HELPPP WILL MARK AS BRAINLIEST
Answer: Spun yarn is made by twisting staple fibers together
To make a cohesive thread Or “single”. Twisting fibers, into yarn in the process called spinning can be dated back to the upper Paleolithic. Yarn spinning was one of the first processes to be industrialized.
Explanation: