Which statement correctly describes whether a compound is a pure substance? A compound is not a pure substance because each of its molecules is made up of the atoms of two or more different elements. A compound is a pure substance because its molecule cannot be broken down into simpler particles by physical means. A compound is not a pure substance because it is not an element, and only elements are pure substances. A compound is a pure substance because it consists of two different elements, which are pure substances.
Answers
Answer is: A compound is a pure substance because its molecule cannot be broken down into simpler particles by physical means.
Pure substance is made of only one type of atom (element) or only one type of molecule, it has definite and constant composition with distinct chemical properties. Pure substances can be separated chemically, not physically, that is difference between pure substances and mixtures.
Electrolysis of water (pure substance) is the chemical separation, because from one molecule (water) two molecules (hydrogen and oxygen) are produced. Water is separeted into two molecules:
Reaction of reduction at cathode: 2H⁺(aq) + 2e⁻ → H₂(g).
Reaction of oxidation at anode: 2H₂O(l) → O₂(g) + 4H⁺(aq) + 4e⁻.
Answer:
- ANSWER:B
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A heterogeneous mixture is one in which substances are evenly distributed and have a uniform composition
when the aim is to show electron distributions in shells
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An orbital notation is more appropriate if you want to show how the electrons of an atom are distributed in each subshell. This is because there are some atoms that have special electronic configurations that aren't obvious in just written configurations.
Answer:
d
Explanation:
on edg 2020
Answers
Mole measure the number of elementary entities of a given substance that are present in a given sample. Therefore, 311.98 grams is the mass of 2.65 x 10²⁴ molecules of Cl .
What is mole?
The SI unit of amount of substance in chemistry is mole. The mole is used to measure the quantity or amount of substance. We know one mole of any element contains 6.022×10²³ atoms which is also called Avogadro number.
Mathematically, the formula for mole can be given as
mole =given mass ÷ molar mass
Moles of Cl = 2.65 x 10²⁴ / 6.02 x 10²³
= 4.4 moles.
Mass of Cl2 in grams = molar mass of Cl2 x moles of Cl2
= 70.906 x 4.4
= 311.98 grams.
Therefore, 311.98 grams is the mass of 2.65 x 10²⁴ molecules of Cl .
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Mass of Cl2 in grams = molar mass of Cl2 x moles of Cl2
= 70.906 x 4.4
= 311.98 grams.
Hope this helps!
The products have higher potential energy than the reactants, and the enthalpy change is positive.
The products have lower potential energy than the reactants, and the enthalpy change is negative.
The products have lower potential energy than the reactants, and the enthalpy change is positive.
Answers
Ans: The products have lower potential energy than the reactants, and the enthalpy change is negative.
In general, chemical reactions can be broadly classified into two categories:
1) Exothermic
2) Endothermic
Exothermic reactionsproceed with the evolution of heat. Here, the reactants have a higher potential energy which is released as the reaction progresses to form products. Consequently, the products are in a lower energy state. Since energy is released, the enthalpy change will be negative.
In contrast, endothermic reactions proceed with the absorption of heat. Here,the products will be in a higher energy state. Since energy is absorbed, the enthalpy change will be positive.
Answers
N2 + 3H2 -> 2NH3 (Always check if it is balanced).
Ok so we have 2kg of hydrogen conver this to grams and then to moles.
2kg -> 2000g
2000g divide by R.M.M of H2
R.M.M
2H - 2 * 1 -> 2
2000/2 - 1000 moles.
Look at the ratio of H2 to 2NH3.
We see that we get 2NH3 for every H2 therefore the ratio is 1:2.
This means that we HAVE 2000 moles of 2NH3.
At stp. we know that 1 moles = 22.4 Litres
We have 2000 moles that means that we produce 44800 litres of NH3 at stp.
2000 * 22.4 - 44800
Hope this helps :).
Final answer:
The 2.0 kg of H2 after conversion to moles will react according to the balanced chemical equation N2(g) + 3H2(g) → 2NH3(g) to yield roughly 14836 liters of NH3 at standard temperature and pressure (STP). The calculation involves using the principles of stoichiometry and the molar volume of a gas at STP.
Explanation:
The chemistry topic that your question is discussing is known as stoichiometry, which involves the mathematical relationships between reactants and products in a chemical reaction. In this case, we're looking at the reaction of nitrogen gas (N2) with hydrogen gas (H2) to produce ammonia (NH3), which is described with the balanced chemical equation: N2(g) + 3H2(g) → 2NH3(g). This equation tells us that 3 moles of hydrogen react with 1 mole of nitrogen to produce 2 moles of ammonia.
Given that 1 mole of any gas occupies 22.4 liters at standard temperature and pressure (STP), and that we have 2.0 kg or 2000 g of H2, we first need to convert this mass into moles, using the molar mass of hydrogen (1.007 g/mol). So thus, 2000 g /2.014 g/mol gives us approximately 993.5 moles of hydrogen. As per the balanced equation, 3 moles of H2 yields 2 moles of NH3. Therefore, 993.5 moles of hydrogen would yield (993.5 x 2) / 3 = 662.33 moles of ammonia. Multiplying this by the molar volume at STP gives us 662.33 moles x 22.4 L/mol =14836 liters of ammonia.
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b. churches to draw in new patrons who want to view its beauty from inside.
c. reflecting and absorbing light, as well as displaying colorful images.
d. creating mirrored images of light and colors on the surrounding walls of a religious structure.
Answers
Stained glass can be useful for churches to draw in new patrons who want to view its beauty from inside.
What is stained glass?
Stained glass is defined as a glass material which is made colored by means of adding metallic salts during the manufacturing process which imparts color to the glass.
These are used in many decorative purposes like decorating windows . The colors are imparted to the glass by mixing metal oxides into the colorless glass in its melted state.Sometimes fusion of a colored glass with a plain glass to make a stained glass is also used.
Stained glass is also prepared by glass paint where in streaks are introduced in glass by means of light firing in a furnace or a kiln.Silver stain is a range of compounds where in silver compound are mixed with binding substances and then applied to surface of glass,which are then fired in a furnace or in a kiln.
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Cu(s) + S(s) CuS(s)
C6H12O6(s) + 6O2(g) 6CO2(g) + 6H2O(g)
5C2O42-(aq) + 2MnO4-(aq) + 16H+(aq) 10CO2(g) + 2Mn2+(aq) + 2H2O(l)
Ag+(aq) + I-(aq) AgI2(s)
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Answers
Answer : Option A) .
Explanation : The reaction of hydrogen gas with iodine in solid phase will react most rapidly at standard conditions.
A rapid chemical reaction is one where reactants react fast with each other to give the products at the standard temperature and pressure conditions.
In the given choices Iodine is highly reactive as it belongs to the halogen group and also atomic hydrogen is very reactive in nature, when both combine it gives hydrogen iodide which is much stable in nature than the reactants.
when one mole of hydrogen reacts with one mole of iodine it produces 2 moles of hydrogen iodide.
.
H2(g) + I2(s) 2HI(g)
The reaction that do not occur rapidly at standard conditions are
Cu(s) + S(s) CuS(s)
C6H12O6(s) + 6O2(g) 6CO2(g) + 6H2O(g)
5C2O42-(aq) + 2MnO4-(aq) + 16H+(aq) 10CO2(g) + 2Mn2+(aq) + 2H2O(l)
Ag+(aq) + I-(aq) AgI2(s)