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Dahasolnce [82]
3 years ago
7

What is the universe made of? Astronomers face an embarrassing conundrum: they don't know what 95% of the universe is made of.

Chemistry
1 answer:
Citrus2011 [14]3 years ago
4 0

Answer:

I think u understand this answers

You might be interested in
Consider the combustion reaction for octane (C8H18), which is a primary component of gasoline.
DIA [1.3K]

Answer:

1.16 moles CO₂

Explanation:

To find the moles of CO₂, you need to (1) convert grams C₈H₁₈ to moles (via the molar mass) and then (2) convert moles C₈H₁₈ to moles CO₂ (via the mole-to-mole ratio from equation coefficients). It is important that the conversions/ratios are arranged in a way that allows for the cancellation of units. The final answer should have 3 significant figures like the given value.

Molar Mass (C₈H₁₈): 8(12.011 g/mol) + 18(1.008 g/mol)

Molar Mass (C₈H₁₈): 114.232 g/mol

2 C₈H₁₈ + 25 O₂ -----> 16 CO₂ + 18 H₂O
^                                    ^

16.6 g C₈H₁₈            1 mole            16 moles CO₂          
--------------------  x  -----------------  x  -------------------------  = 1.16 moles CO₂  
                              114.232 g          2 moles C₈H₁₈          

3 0
2 years ago
The law of conservation of momentum states that if objects exert forces only on each other, their total momentum is ____________
iren2701 [21]

Answer:

Conserved.

Explanation:

Momentum can be defined as the multiplication (product) of the mass possessed by an object and its velocity. Momentum is considered to be a vector quantity because it has both magnitude and direction.

Mathematically, momentum is given by the formula;

Momentum = Mass * Velocity

The law of conservation of momentum states that the total linear momentum of any closed system would always remain constant with respect to time.

This ultimately implies that, the law of conservation of momentum states that if objects exert forces only on each other, their total momentum is conserved.

8 0
3 years ago
Alkali metals react with water to produces what product?
atroni [7]

Answer:

  • <em>Alkali metals react with water to produce </em><u>hydroxide and hydrogen gas</u><u>.</u>

Explanation:

That is a chemical property of <em>alkali metals</em>: they are highly reactive and <em>react </em>vigorously <em>with water</em> to produce the correspondant hydroxide and hydrogen gas.

These are some of those reactions:

  • 2Li (s) + 2H₂O (l)  → 2LiOH (aq) + H₂(g) ↑

  • 2Na (s) + 2H₂O (l)  → 2NaOH (aq) + H₂(g) ↑

  • 2K (s) + 2H₂O (l)  → 2KOH (aq) + H₂(g) ↑

The alkali metals are the elements of group 1 of the periodic table: Li, Na, K, Rb, Cs, and Fr. They have one valence electron which may lose easily to form an ion with charge +1.

7 0
3 years ago
Given an ideal gas has a volume of
fomenos
229.98 degree kelvin.
7 0
3 years ago
Molecular weight of PbCl2 = 278 g/mole Mass of beaker + PbCl2 = 62.19 g Mass of beaker = 57.77 g Mass of PbCl2 per 100 mL = g Mo
levacccp [35]
PbCl2--->Pb2+  +  2Cl-

The  mass   of  PbCl2   is   =mass   of  the  beaker+Pbcl2  minus   mass  of  the  beaker
that  is  62.19-57.77g=  4.42grams

moles  of PbCl2=  4.42g/278g/m0l = 0.0159moles

concentration  of  (Pb2+)
since  mole  ratio  of  PbCl2  to  Pb2+  is   1:1  therefore  the  moles  of  Pb2+  is  also  0.0159moles
concentration  =0.0159/100 x1000=0.159M

concentration  of  CI-  is  two  time  that  of  Pb2+  from  the  equation  above  therefore  concentration   of  Cl-  =  0.159 x2  =0.318M
7 0
3 years ago
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