the boiling point of isopropyl alcohol is 82.5°C. a student conducts an experiment and finds a boiling point of 83.1°C. what is the students percent error in this experiment?
A.0.6%
B. 0.7%
C. 1.0%
D. 99.3%
Answer:
B. 0.7%
Explanation:
Given data:
Actual boiling point = 82.5°C
Experimental boiling point = 83.1°C
Percent error = ?
Solution:
Formula:
Percent error = ( actual value - experimental value / actual value )×100
by putting values,
Percent error = (82.5°C - 83.1 °C /82.5°C) × 100
Percent error = 0.007 × 100
Percent error = 0.7 %
Negative sign shows that experimental value is greater than accepted value. It can not written in result.
GUYSS JUST ONE QUESTION PLEASE HELPPP!!!!!!
Explanation:
done
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For the cold pack shown below, the temperature on the outside surface has dropped considerably from its initial temperature of 25 °C. Which of the following provides the best explanation for this temperature decrease?
Answer:
The correct answer is D
Explanation:
In an endothermic process, energy travels from the surroundings into the system. The decrease in the temperature on the outside of the bag indicates that energy has moved from the surroundings into the system.
The other answers are incorrect. A bag cannot release “cold” into the surroundings since cold refers to the absence of heat. The surroundings become colder when heat is removed. Option B is incorrect because the cooling is due to the cold pack absorbing heat energy from its surroundings. Option C is incorrect because a cold pack absorbs heat energy from the surroundings, not vice versa.
The surroundings are losing energy and the thermometer is measuring the temperature of the surroundings as the cold pack shows an endothermic process. Therefore, Option (D) is correct.
What is an endothermic reaction?Endothermic reactions are those in which the reactants absorb heat energy from their surroundings to form products. Endothermic reactions reduce the temperature of their surroundings and create a cooling effect. Physical processes can be endothermic in nature as well, for example, ice cubes absorb heat from their surroundings to form liquid water.
Endothermic reactions include the making of chemical bonds through the absorption of energy from the surroundings. On the other hand, exothermic reactions are in which the liberation of heat energy is generated from bond breakage.
The temperature of the cold pack is lower than the temperature of the surroundings. So the heat energy will be traveled from the surroundings to the cold pack.
Therefore, the temperature of the surroundings will fall as heat transfers to the cold pack.
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Which nuclear equation represents a spontaneous decay?
(1) Rn 21% Po + He
(2) 13 Al + He 18P + on
(3) 235 U + in ~ 13% Ba + Kr + 3n
(4) Li + H → He + He
a. 1
b. 2
C 3
d. 4
Answer:
a. 1
Explanation:
Radon is a member of group 18. It is an odorless heavy gas, that emanates from materials that contain uranium.
Rn is a decay product of 226-Ra, a member of the uranium decay series. The spontaneous decay of Rn decay leads to the emission of an alpha particle.
Rn has a half-life of about 3.8 days and its decay product is 218Po.
The nuclear reaction which shows a spontaneous decay is Rn 21% Po + He.
What is spontaneous reaction?
Those reaction in which value of their enthalpy change and change in Gibb's free energy is negative, are spontaneous in nature.
Among all of the given reaction, only first reaction is spontaneous in nature because the given element Radon (Rn) is the product of the decay of uranium series. And in this reaction energy is emitted in the form of alpha particles.
Hence, option (1) is correct.
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12. Draw the lewis structure for the element to help you answer the question *
Answer:hope it helps
Explanation:
what chemical reaction type is Pb + 2 H3PO4 --> 3 H2 + Pb3(PO4)2
Answer:
single displacement reaction
Explanation:
it is because an atom(Pb) dispalces another atom(H) in H3PI4
The given chemical reaction is single displacement reaction.
What is single displacement reaction?When one element in a molecule gets replaced by another, is therefore called a single displacement reaction.
The given reaction is Pb + 2 H3PO4 → 3 H2 + Pb3(PO4)2
It can be seen that when lead is treated with H3PO4 then it will give Pb3(PO4)2 and hydrogen reaction. It is a kind of single displacement reaction.
Therefore, the given reaction is single displacement reaction.
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what is ionizable hydrogen and why we say it replaceable hydrogen
Answer:
only hydrogen atoms that are part of a highly polar covalent bond are ionizable. The hydrogen atom is attracted to the lone pair of electrons in a water molecule when HCl is dissolved in water. The result is that the H−Cl bond breaks, with both bonding electrons remaining with the Cl, forming a chloride ion.
Explanation:
Answer:
In an acid molecule, hydrogen atoms may be substituted by metal atoms.
Explanation:
It is ionizable only to hydrogen atoms that are part of a strongly polar covalent bond. As HCl is dissolved in water, the hydrogen atom is drawn to the lone pair of electrons in a water molecule. The effect is that the H-Cl bond splits, with the Cl remaining with both bonding electrons, forming a chloride ion.
Iodine monochloride (ICl) has a higher boiling point than bromine (Br2) partly because iodine monochloride is a(n)
Answer: polar molecule.
Explanation:
The boiling point is the temperature at which the vapor pressure of a liquid equals the external pressure surrounding the liquid. The boiling point is dependent on the type of forces present.
Iodine monochloride (ICl) is a polar molecule due to the difference in electronegativities of iodine and chlorine. Thus the molecules are bonded by strong dipole dipole forces. Thus a higher temperature is needed to generate enough vapor pressure.
Bromine [tex](Br_2)[/tex] is a non polar molecule as there is no electronegativity difference between two bromine atoms. The molecules are bonded by weak vanderwaal forces and thus has low boiling point.
A scientist was working in a nuclear reactor facility and was exposed to radioactive particles. Although the scientist was wearing only basic clothing as protection, she exhibited no symptoms of radiation poisoning. What type of radiation was the scientist most likely exposed to?
Group of answer choices
A. Beta
B. Gamma
C. Alpha
D. None of the above
Answer:
C. Alpha
Explanation:
In a nuclear reactor facility, radioactive decay takes place, which is any several processes by which unstable nuclei emit subatomic particles and ionizing radiation and disintegrate into one or more smaller nuclei. A scientist working under this condition is likely to be exposed to alpha particles because it contains a minimal absorption range and they are the least dangerous regarding external exposure.