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tino4ka555 [31]
3 years ago
8

Which of these substances are elements?

Chemistry
2 answers:
Aleks04 [339]3 years ago
8 0
An element is a species of atom that has the same amounts of electrons and protons in their nuclei. To know which of these substances are elements, we can look it up in the periodic table of elements. The elements are as follows:

1.silicon
2.lead
3.silicone
5.iodine

Andru [333]3 years ago
8 0

Answer is:

1. silicon.

2. lead.

5. iodine.

Silicon (symbol: Si) is an element with atomic number 14 (14 protons).

Lead (Pb) is an element with atomic number 82.

Iodine (I) is an element with atomic number 53.

Silicone is a compound (polymer) made of silicon, oxygen, hydrogen, carbon and other elements.

Quartz is a compound (mineral) made of silicon and oxygen atoms.

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For the reaction, calculate how many grams of the product form when 1.8 g of cao completely reacts. assume that there is more th
ludmilkaskok [199]
Balance Chemical Equation is,

                            <span>CaO </span>₍s₎  <span>+  CO</span>₂ ₍g₎   <span>→   CaCO</span>₃ ₍s₎

According to Equation

56.07 g of CaO when reacted with excess CO₂ produces  =  100.08 g of CaCO₃.

Then,

    1.8 g of CaO is reacted with excess CO₂  =  X g of CaCO₃ will produce.

Solving for X,
                               X  =  (100.08 g × 1.8 g) ÷ 56. 07 g

                               X  =  3.21 g of CaCO₃
5 0
3 years ago
Some COCl2 is placed in a sealed flask and heated to 756 K. When equilibrium is reached, the flask is found to contain COCl2 (7.
o-na [289]

Answer:

9.044\times 10^{-3} is the value of the equilibrium constant for this reaction at 756 K.

Explanation:

COCl_2\rightleftharpoons CO+Cl_2

Equilibrium concentration of COCl_2

[COCl_2]=7.40\times 10^{-4} M

Equilibrium concentration of CO

[CO]=3.76\times 10^{-2} M

Equilibrium concentration of Cl_2

[Cl_2]=1.78\times 10^{-4} M

The expression of an equilibrium constant can be written as;

K_c=\frac{[CO][Cl_2]}{[COCl_2]}

=\frac{3.76\times 10^{-2}\times 1.78\times 10^{-4}}{7.40\times 10^{-4}}

K_c=9.044\times 10^{-3}

9.044\times 10^{-3} is the value of the equilibrium constant for this reaction at 756 K.

5 0
3 years ago
A chemical reaction occurs between Calcium, Oxygen, and Chlorine. The reaction is demonstrated:
ad-work [718]

Answer:

D.

Double replacement, CaO + Cl2O

Explanation:

8 0
3 years ago
Read 2 more answers
Calculate the moles of SO₂ produced when 5 moles of FeS₂ reacts according to the equation: 4FeS₂+ 11O₂ → 2Fe₂O₃ + 8SO₂
Gala2k [10]

Answer:

10 moles of SO₂ are produced when 5 moles of FeS₂

Explanation:

Stoichiometry: it is the theoretical proportion in which the chemical species are combined in a chemical reaction. The stoichiometric equation of a chemical reaction relates molecules or number of moles of all the reagents and products that participate in the  reaction.

In other words, stoichiometry establishes relationships between the molecules or elements that make up the reactants of a chemical equation with the products of said reaction. The relationships established are molar relationships (that is, moles) between the compounds or elements that make up the chemical equation.

The stoichiometric coefficients of a chemical reaction indicate the proportion in which said substances react.

Taking into account the above, you can apply the following rule of three: by stoichiometry if 4 moles of FeS₂ produce 8 moles of SO₂, then when reacting 5 moles of FeS₂ how many moles of SO₂ will they produce?

moles of SO_{2} =\frac{5 moles of FeS_{2} *8moles of SO_{2}}{4 moles of FeS_{2}}

moles of SO₂= 10

<u><em>10 moles of SO₂ are produced when 5 moles of FeS₂</em></u>

7 0
3 years ago
Magnesium sulfate can be made by reacting magnesium metal with an acid . A gas is also produced . Name this gas
jekas [21]

Answer:

the answer to your question is

Explanation:

hydorgen

Mg+ H2SO4 --------> MgSO4 + H2

8 0
2 years ago
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