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4 years ago

Just a question... Worth 45 points!

Chemistry

2 answers:

Lerok [7]4 years ago

7 0

The insulator that would most likely keep the cup warmer is the two layers of foil.

Alex787 [66]4 years ago

5 0

I believe the cup within another would keep it warm the longest because it would insulate the heat within the main cup, that or you could just leave it in a microwave ^-^

Hope this sorta helps XD

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The energy transfer between the system and the surroundings, in the form of heat at constant pressure is described by which of t

kicyunya [14]

I think the answer would be d but not 100% sure

4 0

3 years ago

Which chemical is responsible for opening the hair cuticle?

SashulF [63]

Peroxide is the chemical responsible for opening the hair cuticle

6 0

3 years ago

Consider a neutrally charged atom that has an atomic mass number of 80, which includes 35 neutrons. how many electrons does this

ivanzaharov [21]

Atomic mass number is the number of protons and neutrons. Subtract 80-35=45 is the number of protons. Because the atom is neutrally charged, the number of protons must equal the number of electrons, so there are 45 electrons.

5 0

3 years ago

Read 2 more answers

Is the bond C=O polar or non polar

rewona [7]

Answer:

Non Polar

Explanation:

Non Polar molecule because of its linear symmetric shape

6 0

3 years ago

Read that From picture and tell me the answer please

Dafna11 [192]

Answer:

1g Hydrogen

Explanation:

<h3>Getting to the equation:</h3>

Calcium in water reacts vigorously to give a cloudy white Precipitate (compound) called Calcium hydroxide alongwith the evolution of Hydrogen gas.

$\boxed{ \mathsf{Ca + H_2O \rightarrow Ca(OH)_2 + H_2}}$

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

<h3>Balancing the equation: </h3>

This reaction is not in it's balanced form! The number of atoms of Hydrogen on the left is 2 while that on the right is 4,I.e.,they're not equal.

Adding a 2 in front of H2O solves the problem by making the number of atoms of each element on both the sides equal.

$\mathsf{Ca +2 H_2O \rightarrow Ca(OH)_2 + H_2}$

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

<h3>Observations:</h3>

Looking into the equation more carefully, we see:

1 atom of Calcium reacts with 2 molecules of water to give 1 molecule of Calcium Hydroxide alongwith 1 molecule of Hydrogen gas.

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

<h3>Gram atomic and molecular masses </h3>

Mass of one atom of Calcium = it's gram atomic mass

= 40 g

Mass of one "molecule" of Hydrogen

= it's Gram molecular mass

= gram mass of one atom × number of atoms in one molecule

= 1 × 2

= 2 g

So,

according to our observation:

One atoms of Calcium gives one molecule of Hydrogen (during the particular reaction)

=> 40g of Calcium gives = 2g of Hydrogen

•°• 1 g of Calcium gives = $\frac{2}{40}$

= $\frac{1}{20}$ g Hydrogen

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

<h3>Answer:</h3>

We're provided with 20g of Calcium,

=> 20g of Calcium gives = 20 × $\frac{1}{20}$ g H2

= 1 g H2

_______________

Hope this helps!

6 0

2 years ago