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4 years ago

Which pack has the greatest change in enthalpy, warm packs (such as hand warmers) or cold packs (such as an ice pack)?

1 answer:

3 0

Enthalpy is the change in energy. A cold pack will react endothermically and enthalpy will be positive and a heat pack will have negative enthalpy. You cannot determine which has more change in enthalpy unless you measure the temperature change. Eg. a heat pack went from 25c to 35c will have greater change in enthalpy then a cold pack going from 25 to 20c because the net temperature difference is greater

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Why should you add acid to water rather than add water to acid when preparing solutions?.

victus00 [196]

Answer:It is because acid and water react violently exothermically, producing heat and occasionally melting the fluid.

Explanation:

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3 years ago

A buffer is prepared such that [H2PO4-] = 0.095M and [HPO42-] = 0.125M? What is the pH of this buffer solution? (pKa = 7.21 for

ANTONII [103]

Answer:

pH of the buffer is 7.33

Explanation:

The mixture of the ions H₂PO₄⁻ and HPO₄²⁻ produce a buffer (The mixture of a weak acid, H₂PO₄⁻, with its conjugate base, HPO₄²⁻).

To find pH of a buffer we use H-H equation:

pH = pka + log [A⁻] / [HA]

<em>Where A⁻ is conjugate base and HA weak acid.</em>

<em />

For the H₂PO₄⁻ and HPO₄²⁻ buffer:

pH = pka + log [HPO₄²⁻] / [H₂PO₄⁻]

Computing values of the problem:

pH =7.21 + log [0.125M] / [0.095M]

pH = 7.33

<h3>pH of the buffer is 7.33</h3>

<em />

4 0

3 years ago

Where do diamonds come from?

Ad libitum [116K]

Answer: Diamonds were first discovered and mined in India over 2,400 years ago.

Explanation: Over time, diamonds were found in many other areas around the world, including many in Africa. In today's trade, Africa, Russia, Australia, and Canada produce the most diamonds.

~Wonderopolis

7 0

3 years ago

Read 2 more answers

What is the simplest whole number ratio of atoms in a molecule or formula unit called?

astra-53 [7]

The empirical formula

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3 years ago

Part A What are plate boundaries at which lithospheric plates that a) move toward each other, b) move past each other, and c) mo

Alex787 [66]

Answer:

a. Convergent boundary

b. Transform boundary

c. Divergent boundary

Explanation:

Convergent boundary are boundary where tectonic plates collide with each other. This kind of boundary might involve a collision between continental and oceanic plates, continental and continental plates and oceanic and oceanic plates. Generally, convergent boundary are regions for mountainous structures . Example of mountain formed through convergence are mountain Everest and Himalayas .

Transform boundary are boundary where tectonic plates move past each other . This kind of boundary is responsible for the creation of Extensive Fault like the San Andrea Fault.

Divergent boundary are boundary where tectonic plates move away from each other. The diverging movements brings about oceanic ridges. The mid oceanic ridges is where magma rises to the surface to form a new crust. The up welling of this magma causes further separation of this plates.

The picture above illustrate convergent, divergent and transform boundary.

4 0

4 years ago