Can someone help me please

Some instant cold packs contain ammonium nitrate and a separate pouch of water. When the pack is activated by squeezing to break

KIM [24]

Answer:

a) Endothermic

b) T₂ = 53.1 ºC

Explanation:

a) We are told that when the ammonium nitrate dissolves in water the pack gets cold so the system is absorbing heat from the surroundings and by definition it is an endothermic process.

b) Recall that the heat, Q, is given by the formula:

Q = mcΔT where m is the mass of water,

c is the specific heat of water, and

ΔT is the change in temperature

We can determine the value for Q since we are given the heat of solution for the ammonium nitrate. From there we can calculate ΔT and finally answer our question.

Molar mass NH₄NO₃ = 80.04 g/mol

moles NH₄NO₃ = 50.0 g/ 80.04 g/mol = 0.62 mol

Q = 25.4 kJ/mol x 0.62 mol = 15.87 kJ = 15.87 kJ x 1000 J = 1.59 x 10⁴ J

Q = mcΔT ⇒ ΔT = Q/mc

ΔT = 1.59 x 10⁴ J/ (135 g x 4.184 J/gºC ) = 28.1 ºC

T₂- T₁ = ΔT ⇒ T₂ = ΔT + T₁ = 28.1 ºC +25.0 ºC = 53.1 ºC

5 0

4 years ago

State two example of how engineers use their knowledge of atoms to create new technologies?( I am giving you high points for thi

Eduardwww [97]

The correct answer to this open question is the following.

Two examples of how engineers use their knowledge of atoms to create new technologies would be the following.

1.- Engineers can develop new medicines for chronic diseases when they use their knowledge about atoms. With new technologies and different scientific approaches, this new molecular medicine can be more effective in the treatment of terrible diseases that affect humans. The challenge lies in how to make these new medicines more affordable to all kinds of people, not only rich people.

2.- Engineers can also apply their knowledge about atoms to improve the water conditions so more people can have freshwater. Engineers that specialize in the environment can research the properties of water molecules and atoms, so they can develop new ways to purify and improve the quality of water, that we know that water scarcity is a major problem in many parts of the world.

4 0

4 years ago

PLSSS HELP ANYONE ASAP!

algol [13]

B I hope it’s right I don’t really help a lot but yeah lol

7 0

3 years ago

Redox titrations are used to determine the amounts of oxidizing and reducing agents in solution. For example, a solution of hydr

xxTIMURxx [149]

Answer:

0.374 g

Explanation:

Hello,

Since both the molarity and the volume allows us to know the moles of potassium permanganate, and we already have the balanced chemical reaction, the stoichiometric procedure that is attached in the picture, is developed to substantiate the the titrated mass of hydrogen peroxide was 0.374 g.

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