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topjm [15]
2 years ago
12

Which word describes AH for exothermic reactions? O negative O small positive O zero

Chemistry
1 answer:
Leokris [45]2 years ago
7 0

Answer:

negative

Explanation:

Exothermic reaction - energy is out of system, so energy of system becomes smaller, and ΔH<0.

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Solve for V2 when P1 = 1.0 atm V1 = 22.4 L and P2 = 4.0 atm <br> This is a Boyle’s law gas problem
morpeh [17]
P1/V1=P2/V2
1/22.4=4/x
X=4 multiple by 22.4
V2=89.6L
3 0
3 years ago
The heat of fusion for ice is 334 joules per gram. Adding 334 joules of heat to one gram of ice at STP will
yulyashka [42]

C) change to water at the same temperature

Explanation:

Adding 334Joules of heat to one gram of ice at STP will cause ice to change to water at the same temperature.

  • The heat of fusion is the amount of energy needed to melt a given mass of a solid
  • It is also conversely the amount of energy removed from a substance to freeze it.
  • The addition of this energy does not cause a decrease or increase in temperature.
  • Only a phase change occurs.

Learn more:

Heat of fusion brainly.com/question/4050938

#learnwithBrainly

3 0
3 years ago
Which of the following is the correct formula for Ca2+ reacting with NO2??
mariarad [96]

Answer:

B. Ca(NO2)2

Explanation:

Ions (charged atoms) combine with one another to form stable ionic compounds. In this case, calicium ion (Ca2+) is said to react with NO2, which has a charge of -1 i.e. +1-1(2) = 1-2 = -1.

This means that calcium has a charge of +2 while nitrite ion has charge of -1, hence, when they combine, they exchange their charges, which become their subscript as follows:

Ca2+ + NO2- → Ca(NO2)2

Ca(NO2)2 is a stable ionic compound called calcium nitrite. Notice that it takes two atoms of NO2- to react with one atom of Ca2+.

5 0
3 years ago
An excess of Ba(No3)2 reacts with 250ml of H2SO4 solution to give 0.55g of BaSo4.determine The concentration in moles per litre
Wewaii [24]
Chemical reaction: Ba(NO₃)₂ + H₂SO₄ → BaSO₄ + 2HNO₃.
V(H₂SO₄) = 250 mL ÷ 1000 mL/L = 0,25 L.
m(BaSO₄) = 0,55 g.
n(BaSO₄) = m(BaSO₄) ÷ M(BaSO₄).
n(BaSO₄) = 0,55 g ÷ 233,38 g/mol.
n(BaSO₄) = 0,00235 mol.
From chemical reaction: n(BaSO₄) : n(Ba(NO₃)₂) = 1 : 1.
n(Ba(NO₃)₂) = 0,00235 mol.
c(Ba(NO₃)₂) = n(Ba(NO₃)₂) ÷ V.
c(Ba(NO₃)₂) = 0,00235 mol ÷ 0,25 L.
c(Ba(NO₃)₂) = 0,0095 mol/L.
7 0
3 years ago
What volume (in L) will a 32 g sample of butane gas, C4H10(g), occupy at a temperature of 45.0 oC and a pressure of 728 mm Hg?
larisa86 [58]

Answer:

15.0 L

Explanation:

To find the volume, you need to use the Ideal Gas Law:

PV = nRT

In this equation,

-----> P = pressure (mmHg)

-----> V = volume (L)

-----> n = moles

-----> R = Ideal Gas constant (62.36 L*mmHg/mol*K)

-----> T = temperature (K)

To calculate the volume, you need to (1) convert grams C₄H₁₀ to moles (via the molar mass), then (2) convert the temperature from Celsius to Kelvin, and then (3) calculate the volume (via the Ideal Gas Law).

Molar Mass (C₄H₁₀): 4(12.011 g/mol) + 10(1.008 g/mol)

Molar Mass (C₄H₁₀): 58.124 g/mol

32 grams C₄H₁₀              1 moles
-------------------------  x  -----------------------  = 0.551 moles C₄H₁₀
                                    58.124 grams

P = 728 mmHg                      R = 62.36 L*mmHg/mol*K

V = ? L                                    T = 45.0 °C + 273.15 = 318.15 K

n = 0.551 moles

PV = nRT

(728 mmHg)V = (0.551 moles)(62.36 L*mmHg/mol*K)(318.15 K)

(728 mmHg)V = 10922.7632

V = 15.0 L

6 0
1 year ago
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