1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Pavel [41]
3 years ago
5

Which best describes an element

Chemistry
1 answer:
-Dominant- [34]3 years ago
8 0

Answer:

a pure substance

Explanation:

cant be broken down into any more  simpler substances

You might be interested in
At 20 ∘C the vapor pressure of benzene C6H6 is 75 torr and that of toluene C7H8 is 22 torr. Assume that benzene and toluene fo
Olegator [25]

Answer:

a) Xbenzene = 0.283

b) Xtoluene = 0.717

Explanation:

At T = 20°C:

⇒ vapor pressure of benzene (P*b) = 75 torr

⇒ vapor pressure toluene (P*t) = 22 torr

Raoult's law:

  • Pi = Xi.P*i

∴ Pi: partial pressure of i

∴ Xi: mole fraction

∴ P*i: vapor pressure at T

a) solution: benzene (b) + toluene (t)

∴ Psln = 37 torr;   at T=20°C

⇒ Psln = Pb + Pt

∴ Pb = (Xb)*(P*b)

∴ Pt = (Xt)*(P*t)

∴ Xb + Xt = 1

⇒ Psln = 37 torr = (Xb)(75 torr) + (1 - Xb)(22 torr)

⇒ 37 torr - 22 torr = (75 torr)Xb - (22 torr)Xb

⇒ 15 torr = 53 torrXb

⇒ Xb = 15 torr / 53 torr

⇒ Xb = 0.283

b) Xb + Xt = 1

⇒ Xt = 1 - Xb

⇒ Xt = 1 - 0.283

⇒ Xt = 0.717

6 0
3 years ago
The standard enthalpy of formation for glucose [c6h12o6(s)] is −1273.3 kj/mol. what is the correct formation equation correspond
balu736 [363]
The standard formation equation for glucose C6H12O6(s) that corresponds to the standard enthalpy of formation or enthalpy change ΔH°f = -1273.3 kJ/mol is 
     C(s) + H2(g) + O2(g) → C6H12O6(s)
and the balanced chemical equation is 
     6C(s) + 6H2(g) + 3O2(g) → C6H12O6(s)

Using the equation for the standard enthalpy change of formation 
     ΔHoreaction = ∑ΔHof(products)−∑ΔHof(Reactants)
     ΔHoreaction = ΔHfo[C6H12O6(s)] - {ΔHfo[C(s, graphite) + ΔHfo[H2(g)] + ΔHfo[O2(g)]}

C(s), H2(g), and O2(g) each have a standard enthalpy of formation equal to 0 since they are in their most stable forms:
     ΔHoreaction = [1*-1273.3] - [(6*0) + (6*0) + (3*0)]
                           = -1273.3 - (0 + 0 + 0)
                           = -1273.3
8 0
3 years ago
Why is the bond angle in a water molecule less than the bond angle of methane
Annette [7]
The bond angle in the Water Molecule is approx. 104.5 degrees. The methane molecule is approx. 109.5 degrees. The differences, is due to the force from the surrounding molecules and atoms. For example the Lone pairs of electrons.

6 0
4 years ago
Solve for b if R = x(A + B)
Tatiana [17]

This is what I got. Hope it helps :)

7 0
3 years ago
Select the correct answer. When an atom in a reactant loses electrons, what happens to its oxidation number? A. Its oxidation nu
vfiekz [6]

Answer:

C. Its oxidation number increases.

Explanation:

  • <em><u>Oxidation is defined as the loss of electrons by an atom while reduction is the gain of electrons by an atom</u></em>.
  • Atoms of elements have an oxidation number of Zero in their elemental state.
  • When an atom looses electrons it undergoes oxidation and its oxidation number increases.
  • For example, <em><u>an atom of sodium (Na) at its elemental state has an oxidation number of 0. When the sodium atom looses an electrons it becomes a cation, Na+, with an oxidation number of +1 , the loss of electron shows an increase in oxidation number from 0 to +1.</u></em>
8 0
3 years ago
Read 2 more answers
Other questions:
  • How many grams of oxygen is needed to completely react with 9.30 moles of aluminum
    15·1 answer
  • What is the minimum amount of energy a plant<br>must absorb to produce 15.0 g of glucose?​
    9·1 answer
  • What is the value for ΔS°reaction for the following reaction, given the standard entropy values
    11·2 answers
  • How do I find the electronegativity of an element
    10·1 answer
  • What elements react the most? Like have the most reactivity.
    12·1 answer
  • Compute the equilibrium constant at 25 ∘C for the reaction between Sn2+(aq) and Cd(s), which form Sn(s) and Cd2+(aq). Express yo
    8·1 answer
  • How could you determine which household substances are acids, bases, or neutral substances?​
    11·1 answer
  • Given the atomic mass of select elements, calculate the molar mass of each salt. Element Molar mass (g/mol) Beryllium (Be) 9.012
    5·1 answer
  • Explain why clouds are generally observed to form only in the troposphere?
    8·2 answers
  • Which of the following most likely happens when thermal energy is removed from a chemical reaction?
    15·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!