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aleksklad [387]
3 years ago
6

The millions of fossils that scientists have collected are called the fossil __.

Chemistry
1 answer:
loris [4]3 years ago
5 0

Answer:

record

Explanation:

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What is the normal boiling point of an aqueous solution that has a freezing point of ?5.92?c?
Kitty [74]
Yes it is c know need anymore help




3 0
3 years ago
Calculate the amount of heat needed to boil 120.g of acetic acid (HCH3CO2), beginning from a temperature of 16.7°C.
evablogger [386]

Answer:

The total amount of heat needed = 72.2116  kJ

Explanation:

Given that ;

the mass of acetic acid = 120.0 g

The initial temperature T_1 = 16.7 °C  = (16.7 + 273.15 ) K = 298.85 K

The standard molar mass of acetic acid = 60.052  g/mol

Thus ; we can determine the number of moles of acetic acid;

number of moles of acetic acid = mass of acetic acid/ molar mass of acetic acid

number of moles of acetic acid = 120.0 g/ 60.052 g/mol

number of moles of acetic acid =  1.998 moles

For acetic acid:

The standard boiling point  T_2 = 118.1 °C = ( 118.1 + 273.15 ) K = 391.25 K

The enthalpy of vaporization of acetic acid \Delta H_{vap} = 23.7 kJ/mol

The heat capacity of acetic acid   c = 2.043  J/g.K

The change in temperature Δ T = T_2 - T_1

Δ T = (391.25 - 289.85)K

Δ T = 101.4 K

The amount of heat needed to bring the liquid acetic acid at 16.7°C to its boiling point is ;

q = mcΔT

From our values above;

q = 120 g ×  2.043  J/g.K × 101.4 K

q = 24859.2  J

q = 24859 /1000 kJ

q = 24.859 kJ

we have earlier calculated our number of moles o f acetic acid to be 1.998 moles;

Thus;

The needed amount of heat = \Delta_{vap} *numbers \ of  \ moles

The needed amount of heat = 23.7 \ kJ/mol * 1.998 \ moles

The needed amount of heat = 47.3526 kJ

Hence;

The total amount of heat needed = 24.859 kJ + 47.3526 kJ

The total amount of heat needed = 72.2116  kJ

4 0
3 years ago
I will give brainliest and 76 points
katen-ka-za [31]

Answer:

number 5 is the answer

Explanation:

8 0
3 years ago
A physical change is chemically the same after the experiment.<br> True<br> False
Elan Coil [88]

Answer: True

Explanation:

7 0
3 years ago
_Cuo +H, → _Cu + _H,0
Elena-2011 [213]
<h3>Answer:</h3>

CuO(s) + H₂(g) →  Cu(s) + H₂O(l)

<h3>Explanation:</h3>
  • Assuming the reaction is the reduction of CuO by H₂
  • Then the balanced equation for the reaction is;

CuO(s) + H₂(g) →  Cu(s) + H₂O(l)

  • The equation shows the reducing property of hydrogen gas, such that hydrogen reduces metal oxides such as copper(ii)oxide to the respective metals.
  • The law of conservation requires chemical equations to be balanced so as the mass of reactants will be equal to that of products.
  • In this case; there is 1 copper atom, 1 oxygen atom and 2 hydrogen atoms on both side of the equation and thus the equation is balanced.

3 0
3 years ago
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