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Gelneren [198K]
3 years ago
13

Archeology has shown that accent people _

Chemistry
1 answer:
mrs_skeptik [129]3 years ago
3 0

Answer:

are ancient

Explanation:

its true.

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Suppose that 0.48 g of water at 25 ∘ C condenses on the surface of a 55- g block of aluminum that is initially at 25 ∘ C . If th
mamaluj [8]

Answer:

49^oC

Explanation:

At 25^oC, the heat of vaporization of water is given by:

\Delta H^o_{vap} = 43988 J/mol\cdot \frac{1 mol}{18.016 g} = 2441.6 J/g

The water here condenses and gives off heat given by the product between its mass and the heat of vaporization:

Q_1 = \Delta H^o_{vap} m_w

The block of aluminum absorbs heat given by the product of its specific heat capacity, mass and the change in temperature:

Q_2 = c_{Al}m_{Al}(t_f - t_i)

According to the law of energy conservation, the heat lost is equal to the heat gained:

Q_1 = Q_2 or:

\Delta H^o_{vap} m_w = c_{Al}m_{Al}(t_f - t_i)

Rearrange for the final temperature:

\Delta H^o_{vap} m_w = c_{Al}m_{Al}t_f - c_{Al}m_{Al}t_i

We obtain:

\Delta H^o_{vap} m_w + c_{Al}m_{Al}t_i = c_{Al}m_{Al}t_f

Then:

t_f = \frac{\Delta H^o_{vap} m_w + c_{Al}m_{Al}t_i}{c_{Al}m_{Al}} = \frac{2441.6 J/g\cdot 0.48 g + 0.903 \frac{J}{g^oC}\cdot 55 g\cdot 25^oC}{0.903 \frac{J}{g^oC}\cdot 55 g} = 49^oC

6 0
3 years ago
3. Determine the pH of each of the following solutions. (Hint: See Sample Problem B.) a. 1.0 x 10-2 M HCI c. 1.0 x 10-MHI b. 1.0
densk [106]

Answer:

a. pH = 2 b. pH = 3 c. pH = 1 d. Unanswerable

Explanation:

pH = -log[H+] OR pH = -log{H3O+]

                    and inversely

pOH = -log[OH-]

1. Determine what substance you are working with, (acid/base)

2. Determine whether or not that acid or base is strong or weak.

a. 1.0 x 10^-2M HCl

HCl is a strong acid, therefore it will dissociate completely into H+ and Cl- with all ions going to the H+, therefore, the concentration of HCl and concentration of H+ are going to be equal, meaning we simply take the negative logarithm of the concentration of HCl and that would equal pH

pH = -log[H+]

pH = -log(1.0x10^-2)

pH = 2

b. 1.0 x 10^-3M HNO3

HNO3 like part a, is a strong acid, therefore it would simply require you to take the negative logarithm of the concentration of the compound itself, to find its pH.

pH = -log[H+]

pH = -log(1.0 x 10^-3)

pH = 3

c. 1.0 x 10^-1M HI

Like the previous parts, HI is a strong acid

pH = -log[H+]

pH = -log(0.10)

pH = 1

d. HB isn't an element, nor is it a compound so that would be unanswerable.

3 0
3 years ago
Using the model of the periodic table, which two elements pictured have similar chemical properties?
Murljashka [212]

Answer:

1 and 3

Explanation:

The vertical columns (groups) of the periodic table are arranged such that all its elements have the same number of valence electrons. All elements within a certain group thus share similar properties.

5 0
3 years ago
Read 2 more answers
Which element has 21 neutrons and 20 electrons?
mario62 [17]
Scandium has 21 neutrons
6 0
3 years ago
Read 2 more answers
HELPPPPPPPPP 35 POINTSSSSSS!!!!!
zlopas [31]

Answer:

oxidize

Explanation:

5 0
3 years ago
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