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
BartSMP [9]
3 years ago
15

Physical properties for helium?

Chemistry
1 answer:
s2008m [1.1K]3 years ago
4 0
Helium is a colorless, odorless, tasteless gas. It has a number of unusual properties. For example, it has the lowest boiling point of any element, -268.9°C (-452.0°F). The boiling point for a gas is the temperature at which the gas changes to a liquid.
You might be interested in
Limiting reactants would appreciate the help
Vanyuwa [196]

Answer:

Explanation:

The Limiting Reactant is that reactant which when consumed in a reaction stops the reaction. The other reactants will be in excess and typically considered non-reactive.

To identify the limiting reactant ...

- write and balance the reaction of interest. Express it in standard form. That is, standard form of a reaction is when the coefficients of the balanced equation are in their lowest whole number values. Also, remember that the standard equation is 'assumed' to be at STP conditions (0°C & 1atm).

- convert all given reactant values to moles

- divide each reactant mole value by the related coefficient of the the balanced standard equation. The smaller value is the limiting reactant. The remaining reactants will be in excess.  

Your Problem:

Given:        3Ba  +  N₂  => Ba₃N₂

               22.6g    4.2g        ?

moles Ba => 22.6g/137.34g/mol = 0.165 mole Ba

moles N₂ =>    4.2g/14.007g/mol= 0.150 mole N₂

Part A: Determining the Limited Reactant

  • Divide each mole value by respective coefficient ... smallest value is Limiting  Reactant.

Barium => 0.165/3 = 0.055  <=> (Limiting Reactant)

Nitrogen => 0.15/1 = 0.15

  • Barium is the smaller result and is therefore the limiting reactant. This works for ALL limiting reactant type problems. However, be sure to use the mole values calculated first (Ba = 0.165mol & N₂ = 0.150mol) when doing ratio calculations.

Part B: Max (theoretical) amount of Ba₃N₂ produced:

<em>Note: The product yield amounts are based upon the given 'moles' of limiting reactant, NOT the results of the 'divide by respective coefficient' step used to ID the limiting reactant.     </em>

                   3Ba        +          N₂         =>     Ba₃N₂    (3:1 rxn ratio for Ba:Ba₃N₂)

moles      0.165mole        0.150mole         1/3(0.165)mole = 0.055mole Ba₃N₂

                                                                    = 0.055mol(440g/mol) Ba₃N₂

                                                                    = 24.2 grams Ba₃N₂ (as based

                                                                     upon Barium as Limiting Reactant)

Part C: Excess N₂ remaining after reaction stops:

From balanced standard reaction, the reaction ratio for Ba:N₂ is 3moles:1mole. That is, for the moles of Ba consumed, 1/3(moles of Ba) =  moles of N₂ used.

moles of N₂ used = 1/3(0.165)mole = 0.055mole N₂ used  

∴ the amount of N₂ remaining in excess = 0.150mole (given) - 0.055mole (used) = 0.095mole N₂ remaining in excess.

mass N₂ remaining = 0.095mole x 28g/mole = 2.66 grams N₂ remaining in excess.

                   

5 0
3 years ago
E. The element 231/90Th decays to 231/91 Pa. Use the laws of conservation of charge and nucleon number to determine the decay pa
svetoff [14.1K]

Answer:

A negatron emission

Explanation:

We know that radioactivity orginates from instability of the nucleus. When the nucleus is unstable, radioactive emissions are produced in the form of any of these rays:

> Alpha particle emisson

>Beta particles

> Gamma rays

These emissions create a balance for a radioactive decay.

In balancing nuclear reactions we make sure that the charges on both sides must be conserved and that the mass number and atomic numbers conserved too. This means that the sum of mass number and atomic numbers on both side of the reaction must be equal.

The nucleons are the protons and neutrons, they add up to give the mass number. The atomic number is the proton number.

For the given radioactive reaction:

²³¹₉₀Th → ²³¹₉₁Pa + ?

From this equation, we see that the mass number is conserved but the atomic number is not.

The mass number is the superscript whereas the atomic number is the subscript.

Let's say the decay produces an emission of a particle denoted by X

²³¹₉₀Th → ²³¹₉₁Pa + ᵃₙX

What would the nature of X be?

For the charges and masses to be conserved, X must have mass number of 0 and an atomic number of -1.

Checking:

Mass number:

231 = 231 + a ( a is the mass number)

a = 231 - 231 = 0

Atomic number:

90 = 91 + n

n = 90- 91 = - 1

With X having a mass number of 0 and an atomic number of -1, we have a beta particle emission. Specifically, a negatron has been emitted.

A negatron is denoted as ⁰₋₁β which perfectly makes the equation conserved and suits the description of X.

The complete equation is thus written as:

²³¹₉₀Th → ²³¹₉₁Pa + ⁰₋₁β + energy

6 0
3 years ago
What is the balanced equation for the reaction of a solution of sodium sulfate is mixed with strontium chloride?
natta225 [31]

Answer:

NaSO⁴(ads) ,ganadicate

6 0
3 years ago
What is silicon used for? <br> matches<br> gunpowder <br> glass<br> steel can coating
Irina-Kira [14]

Answer:

steel can coating

Explanation:

7 0
3 years ago
Read 2 more answers
What is the molar mass of fluorine gas, F2?
Paladinen [302]

Answer:

37.99681 g/mol

Explanation:

Hope it helps!

6 0
3 years ago
Read 2 more answers
Other questions:
  • What is the environmental effect of 3NaCl
    12·1 answer
  • The number of electrons that can be held in the first orbit (closest to the nucleus)
    11·2 answers
  • Ravi’s grandmother is suffering from diabetes. Her doctor advised her to take lassi with less fat content. Which of the followin
    13·1 answer
  • How many valence electrons does each of the following atoms have?
    9·1 answer
  • The structure of 3-propylpentane is best described as
    9·2 answers
  • Determine the equilibrium vapor pressure of germanium metal at 508.0 C. The standard enthalpy of vaporization of germanium is 37
    9·1 answer
  • The hydrogen peroxide solution used on cuts and scrapes is 3%. Stronger solutions can cause chemical burns. If you mistakenly bu
    5·1 answer
  • When the number of electrons in an atom changes, then the atom's_______ change.
    7·1 answer
  • Which definition bests describes an hydrogen bond? 
    15·1 answer
  • What is indicated by the methyl-prefix?
    10·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!