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natima [27]
2 years ago
11

What is the best definition of the enthalpy change Hr

Chemistry
1 answer:
Gre4nikov [31]2 years ago
5 0

Answer:

<em>The flow of thermal energy in a system, at constant atmospheric pressure AND at thermodynamic standard temperature and pressure.</em>

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some inkjet printers produce picoliter-sized drops. how many water molecules are there in one picoliter of water? the density of
GrogVix [38]

3.37 x 10¹⁰ molecules

Explanation:

Given parameters:

Volume of water = 1pL = 1 x 10⁻¹²L

Density of water = 1.00g/mL = 1000g/L

Unknown:

Number of water molecules = ?

Solution:

To solve this problem, we first find the mass of the water molecule in the inkjet.

       Mass of water = density of water x volume of water

Then, the number of molecules can be determined using the expression below:

        number of moles = \frac{mass of water}{molar mass of water}

 Number of molecules = number of moles x 6.02 x 10²³

Solving:

Mass of water = 1 x 10⁻¹² x 1000 = 1 x 10⁻⁹g

Number of moles:

Molar mass of H₂O = 2 + 16 = 18g/mol

Number of moles = \frac{1 x 10^{-12} }{18} = 5.6 x 10⁻¹⁴moles

Number of molecules =  5.6 x 10⁻¹⁴   x   6.02 x 10²³ = 33.7 x 10⁹

                                     = 3.37 x 10¹⁰ molecules

Learn more:

Number of molecules brainly.com/question/4597791

#learnwithBrainly

4 0
3 years ago
Which of these statements is false? (A) Acetylene (ethyne) can be converted to the acetylide anion by treating with a strong bas
Free_Kalibri [48]

Answer:

(C) Acetylene (ethyne) can be converted to the acetylide anion by treating with a strong base such as CH₃​​Li.

Explanation:

Acetylene (C₂H₂) can be converted to the acetylide anion (C₂⁻²) when treated with a base because it will donate protons (2H⁺). So it will be a neutralization reaction. NaNH₂ and NaOH are strong bases because they are good electrons donators ( NaNH₂ has pair of electrons on N, and NaOH has the group OH⁻), but CH₃Li has no pair of electrons to donate, so it's not a strong base.

4 0
3 years ago
Which of the Atoms shown has an atomic number four
dimulka [17.4K]

Answer:

B

Explanation:

Atomic # = Protons

it says 4 p in the inside of the orbital

4 0
2 years ago
Chlorine can be prepared in the laboratory by the reaction of manganese dioxide with hydrochloric acid, HCl(aq), as
zubka84 [21]

Answer:

Explanation:

MnO₂(s) + 4 HCl(aq)  = MnCl₂(aq) + 2 H₂O(l) + Cl₂

87 g                                                                     22.4 x 10³ mL

volume of given chlorine gas at NTP or at 760 Torr and 273 K

=  175 x ( 273 + 25 ) x 715 / (273 x 760 )

= 179.71 mL

22.4 x 10³ mL of chlorine requires 87 g of MnO₂

179.4 mL of chlorine will require    87 x 179.4 / 22.4 x 10³ g

= 696.77 x 10⁻³ g

= 696.77 mg .

6 0
3 years ago
Please answer number 2
alexandr402 [8]

Answer:

A

Explanation:

Because Rainwater can get acidic because of the carbonic acid that it contains

8 0
2 years ago
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