Answer:
Approximately [tex]1.95 \times 10^{2}\; \rm J[/tex].
Explanation:
Look up the specific heat of gaseous neon:
[tex]c = 1.03 \; \rm J \cdot g^{-1} \cdot K^{-1}[/tex].
Calculate the required temperature change:
[tex]\Delta T = (37.9 - 20.0)\; \rm K = 17.9\; \rm K[/tex].
Let [tex]m[/tex] denote the mass of a sample of specific heat [tex]C[/tex]. Energy required to raise the temperature of this sample by [tex]\Delta T[/tex]:
[tex]Q = c \cdot m \cdot \Delta T[/tex].
For the neon gas in this question:
[tex]c = 1.03\; \rm J \cdot g^{-1}\cdot K^{-1}[/tex].[tex]m = 10.6\; \rm g[/tex].[tex]\Delta T = (37.9 - 20.0)\; \rm K = 17.9\; \rm K[/tex].Calculate the energy associated with this temperature change:
[tex]\begin{aligned}Q &= c \cdot m \cdot \Delta T \\ &= 1.03\; \rm J \cdot g^{-1}\cdot K^{-1} \times 10.6\; \rm g \times 17.9\; \rm K \\ &\approx 1.95 \times 10^{2}\; \rm J\end{aligned}[/tex].
2.56 x 10^13 molecules of HgO equates to how many moles of HgO?
Explanation:
To find the number of moles in a substance given it's number of entities we use the formula
[tex]n = \frac{N}{L} \\[/tex]
where n is the number of moles
N is the number of entities
L is the Avogadro's constant which is
6.02 × 10²³ entities
We have
[tex]n = \frac{2.56 \times {10}^{13} }{6.02 \times {10}^{23} } \\ \\ \\ = 4.25 \times {10}^{ - 11} \: \: \: moles[/tex]
Hope this helps you
What is the pH of 0.42M aniline?
Answer:
Kb=x^2/0.42-x (eqn to calculate)
basicity (pkb) 9.3
Explanation:
A solution contains some or all of the ions Cu2+, Al3+, K+, Ca2+, Ba2+, Pb2+, and NH4+. The following tests were performed, in order, on the solution.
Addition of 6 M HCl produced no reaction.
Addition of H2S with 0.2 M HCl produced a black solid.
Addition of (NH4)2S produced a white solid.
Addition of (NH4)2HPO4 in NH3 produced no reaction.
The final supernatant when heated produced a purple flame.
Identify which of these ions were present in the solution, which were absent, and for which ones no conclusions can be drawn.
Answer:
See explanation
Explanation:
If we look at the tests to be performed on the compounds carefully, we will notice that;
i) Addition of H2S with 0.2 M HCl produced a black solid. This black solid may result from the reaction;
H2S + Cu2+ ---->CuS(balck solid) + H2
or
H2S + Pb2+ ---->PbS(balck solid) + H2
Hence, Cu2+ or Pb2+ may be present
ii) Addition of (NH4)2S produced a white solid. This means that K^+ may be present because the white precipitate is formed during metathesis.
iii) Potassium ion is known to burn with a purple flame.
Hence the suspected ions are;
Cu2+ , Pb2+ and K^+
Identify the reactants and products in the following chemical equation: Zn +2HCl --> ZnCl2 + H2 *
20 points
A: Reactants: Zn & HCl Products: ZnCl2 & H2
B: Reactants: ZnCl2 & H2 Products: Zn & HCl
C: Reactants: Zn & H2 Products: ZnCl2 & HCl
Answer:
A.
Explanation:
zinc and hydrochloric acid reacts to form zinc chloride and hydrogen.
hope it helps. :)
What is the main difference between rain and hail?
Answer:
Rain is a liquid and hail is a solid.
Which substance has the highest ph?
A. Tomato
B. Unpolluted rainwater
C. Ammonium hydroxide
D. Orange juice
Answer:
c ammonium hydroxide nh4oh has higher ph value and its a base
plz mark me branliest
Answer:
c) ammonium hydroxide
Explanation:
ammonium hydroxide nh4oh has higher ph value, and it is an alkaline
5. Element X exists as diatomic molecules.
In which group of the Periodic
Table is X placed?
A. Group O
B.
Group I
C.
Group II
D.
Group VII
Element X Exists as diatomic molecules . In which group of the Periodic Table is X placed ?
Group VII
Group VII - elements are Fluorine , Chlorine , Bromine and Iodine .
They exist in diatomic molecules as F2 , Cl2 , Br2 and I2 .
Give the systematic (IUPAC) name for each molecule. This molecule has the condensed formula C H 3 C O C H 3. The oxygen atom has a double bond to the center carbon. systematic (IUPAC) name: This molecule has the condensed formula C H 3 C H 2 C H 2 C O C H 3. The oxygen atom has a double bond to carbon. systematic (IUPAC) name:
Answer: The IUPAC name of [tex]CH_3COCH_3[/tex] propan-2-one and [tex]CH_3CH_2CH_2COCH_3[/tex] is pentan-2-one.
Explanation:
The basic rules for naming of organic compounds are :
1. First select the longest possible carbon chain. The longest possible carbon chain should include the carbons of double or triple bonds or functional group.For the number of carbon atom, we add prefix as 'meth' for 1, 'eth' for 2, 'prop' for 3, 'but' for 4, 'pent' for 5, 'hex' for 6, 'sept' for 7, 'oct' for 8, 'nona' for 9 and 'deca' for 10.
2. The naming of alkane is done by adding the suffix -ane, alkene by adding the suffix -ene, alkyne by adding the suffix -yne and ketones by adding the suffix -one.;
3. The numbering is done in such a way that the carbon containing the functional group gets the lowest number. While writing the name, the word root is given first , followed by the position of carbon containing the functional group followed by the suffix.
The IUPAC name of [tex]CH_3COCH_3[/tex] propan-2-one and [tex]CH_3CH_2CH_2COCH_3[/tex] is pentan-2-one.
What is the IUPAC name for the compound shown?
An inventor claims to have developed a new perfume that lasts a long time because it doesn't evaporate. Comment on this claim.
a. This would be impossible to make because the perfume would have to be pressurized in order to not evaporate.
b. This product is sure sweep the market making many happy customers.
c. In order to smell something, the molecules must evaporate and reach your nose. If the new perfume doesn't evaporate, it will not have an odor.
d. A perfume that does not evaporate could be toxic since the molecules never leave the skin.
Answer:
C
Explanation:
Perfume needs to evaporate in order to smell. If this perfume didn't evaporate, it would stay as a liquid and never smell.
It wouldn't be D, as no toxic perfumes is sold.
It's not A because perfume doesn't have to be pressurized in order to not evaporate.
It's not B, as it is a hasty conclusion to the claim. Plus, if the perfume did have an odor, even while not evaporating, the sales would be low as the product is that good.