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3 years ago

How many atoms of gold are in 112 grams of gold?

1 answer:

3 0

Atomic <span>mass gold = 196.96 u.m.a

196.96 g ------------------ 6.02x10</span>²³ atoms
112 g ---------------------- ( atoms)

atoms = 112 x ( 6.02x10²³) / 196.96

atoms = 6.74x10²⁵ / 196.96

= 3.42x10²³ atoms

hope this helps!

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mart [117]

Answer:

reaction B is the best one I would choose

3 0

2 years ago

A 237g sample of molybdnum metal is heated to 100.1 0C and then dropped into an insulated cup containing 244 g of water at 10.0

miv72 [106K]

Answer:

The specific heat of molybdenum is 0.254 joules per gram-Celsius.

Explanation:

We consider the system formed by the molybdenum metal and water as our system, a control mass inside an insulated cup, that is, a container that avoids any energy and mass interactions between system and surroundings.

From statement we notice that metal is cooled down whereas water is heated. According to the First Law of Thermodynamics, we know that:

$Q_{metal} - Q_{water} = 0$

$Q_{metal} = Q_{water}$

Where:

$Q_{water}$ - Heat received by water, measured in joules.

$Q_{metal}$ - Heat released by metal, measured in joules.

Now we expand this identity by definition of sensible heat:

$m_{metal}\cdot c_{metal}\cdot (T_{m,o}-T) = m_{water}\cdot c_{water}\cdot (T-T_{w,o})$

The specific heat of the metal is cleared within equation above:

$c_{metal} = \frac{m_{water}\cdot c_{water}\cdot (T-T_{w,o})}{m_{metal}\cdot (T_{m,o}-T)}$

If we know that $m_{water} = 0.237\,kg$ , $m_{metal} = 0.244\,kg$ , $c_{water} = 4186\,\frac{J}{kg\cdot ^{\circ}C}$ , $T_{w,o} = 10\,^{\circ}C$ , $T_{m,o} = 100.10\,^{\circ}C$ and $T = 15.30\,^{\circ}C$ , the specific heat of molybdenum is:

$c_{metal} = \frac{(0.237\,kg)\cdot \left(4186\,\frac{J}{kg\cdot ^{\circ}C} \right)\cdot (15.30\,^{\circ}C-10\,^{\circ}C)}{(0.244\,kg)\cdot (100.10\,^{\circ}C-15.30\,^{\circ}C)}$

$c_{metal} = 254.119\,\frac{J}{kg\cdot ^{\circ}C}$

The specific heat of molybdenum is 0.254 joules per gram-Celsius.

5 0

3 years ago

What is the conjugate acid in the following equation:

yanalaym [24]

Answer:

HNO₂

Explanation:

An acid is a proton donor; a base is a proton acceptor.

Thus, NO₂⁻ is the base, because it accepts a proton from the water.

H₂O is the acid, because it donates a proton to the nitrite ion.

The conjugate base is what's left after the acid has given up its proton.

The conjugate acid is what's formed when the base has accepted a proton.

NO₂⁻/HNO₂ make one conjugate acid/base pair, and H₂O/OH⁻ are the other conjugate acid/base pair.

NO₂⁻ + H₂O ⇌ HNO₂ + OH⁻

base acid conj. conj.

acid base

5 0

2 years ago

By what mechanism does cyclohexanol react when treated in sulfuric acid and what compound results?A) E 1; methoxycyclohexane B)

tensa zangetsu [6.8K]

Answer:

E 1: cyclohexene

Explanation:

This reaction is an example of the dehydration of cyclic alcohols. The reaction proceeds in the following steps;

1) The first step of the process is the protonation of the cyclohexanol by the acid. This now yields H2O^+ attached to the cyclohexane ring.

2) the water molecule, which a good leaving group now leaves yielding a carbocation. This now leaves a cyclohexane carbocation which is highly reactive.

3) A water molecule now abstracts a proton from the carbon adjacent to the carbocation leading to the formation of cyclohexene and the regeneration of the acid catalyst. This is an E1 mechanism because it proceeds via a carbocation intermediate and not a concerted transition state, hence the answer.

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3 years ago

Explain why there would be a need for lithium batteries?

Leviafan [203]

Answer:

The much higher power density offered by lithium ion batteries is a distinct advantage. Electric vehicles also need a battery technology that has a high energy density. ... Lithium ion cells is that their rate of self-discharge is much lower than that of other rechargeable cells such as Ni-Cad and NiMH forms.

Put this into your own words or teachers will make you redo it

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2 years ago