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3 years ago

13

Which of the following is a pure substance that can be separated by physical means and can’t be decomposed into other substances

by chemical means
A: element
B:molecule
C: compound
D: mixture

1 answer:

Sveta_85 [38]3 years ago

3 0

D. mixture. It isn't joined by chemical bonds

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What is the possible formula of AC if A has 2 valence electrons and C has 7 valence electron?

Brut [27]

AC2

A will lose 2
C will gain 1

Need two Cs to match A

3 0

3 years ago

Calculate the volume, in milliliters, of a 0.211 M solution of NaOH that will completely neutralize each of the following. 2.30

xenn [34]

Answer:

$V_{base}=17.9mL$

Explanation:

Hello,

In this case, as the reaction between sodium hydroxide and sulfuric is:

$2NaOH+H_2SO_4\rightarrow Na_2SO_4+2H_2O$

We can notice a 2:1 molar ratio between the base and the acid, for that reason for the titration at the equivalence point we find:

$n_{base}=2*n_{acid}$

Which in terms of concentrations and volumes is:

$M_{base}V_{base}=2*M_{acid}V_{acid}$

In such a way, solving for the required volume of base we find:

$V_{base}=\frac{2*M_{acid}V_{acid}}{M_{base}} \\\\V_{base}=\frac{2*0.820M*2.30mL}{0.211M}\\ \\V_{base}=17.9mL$

Best regards.

7 0

3 years ago

When potassium hydroxide and barium chloride react, potassium chloride and barium hydroxide are formed. The balanced equation fo

Mashcka [7]

Answer:

The answer to your question is letter C.

Explanation:

Reaction

Potassium hydroxide = KOH

Barium chloride = BaCl₂

Potassium chloride = KCl

Barium hydroxide = Ba(OH)₂

KOH + BaCl₂ ⇒ KCl + Ba(OH)₂

Reactant Elements Products

1 K 1

1 Ba 1

2 Cl 1

1 H 2

1 O 2

The reaction is unbalanced

2KOH + BaCl₂ ⇒ 2KCl + Ba(OH)₂

Reactant Elements Products

2 K 2

1 Ba 1

2 Cl 2

2 H 2

2 O 2

Now, the reaction is balanced

7 0

3 years ago

Read 2 more answers

Ag(s)+CN−(aq)+O2(g)→Ag(CN)−2(aq) Express your answer as a chemical equation. Identify all of the phases in your answer. Express

Lerok [7]

Answer : The balanced redox reaction will be,

$4Ag(s)+8CN^-(aq)+O_2(g)+4H^+(aq)\rightarrow 4Ag(CN)_2^-(aq)+2H_2O(l)$

Explanation :

The given chemical equation is,

$Ag(s)+CN^-(aq)+O_2(g)\rightarrow Ag(CN)_2^-(aq)$

In the half reaction method, the number of atoms in each half reaction and number of electrons must be balanced.

The half reactions in the acidic medium are :

Reduction : $O_2(g)+4H^+(aq)+4e^-\rightarrow 2H_2O(l)$ ......(1)

Oxidation : $Ag(s)+2CN^-(aq)\rightarrow Ag(CN)_2^-(aq)+1e^-$ .......(2)

Now multiply the equation (2) by 4 and then added both equation, we get the balanced redox reaction.

Thus, the balanced redox reaction will be,

$4Ag(s)+8CN^-(aq)+O_2(g)+4H^+(aq)\rightarrow 4Ag(CN)_2^-(aq)+2H_2O(l)$

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4 years ago

What particle is emitted when lead-214, 214 82 pb undergoes natural radioactive decay to bismuth-214, 214 83 bi?

const2013 [10]

A beta particle.<span>β
</span> Looking at the particles before and after for the decay, you'll see that there is a total of 214 neutrons and protons both before and after the radioactive decay. But you'll also see that before the decay, there were 82 protons and after the decay, there are 83 protons. So a neutron was converted to a proton which means that a negative charge had to be emitted, so it's a beta decay where a neutron emits a beta particle (an electron). The beta particle can be represented as a greek beta <span>β</span> followed by a minus sign, giving β-, or as a "e" followed by a minus sign, so e-

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3 years ago