What is 155.4g÷8.70mL, rounded to the correct number of significant figures

What is "Scarcity" <img src="https://tex.z-dn.net/?f=." id="TexFormula1" title="." alt="." align="absmiddle" class="latex-fo

Lana71 [14]

Explanation:

I don't know sorry ok I have some work so I m sorry

4 0

2 years ago

Read 2 more answers

Which would result in radioactive decay? Check all that apply

Gekata [30.6K]

6+2=115 and its good it took test

4 0

3 years ago

Read 2 more answers

The standard unit (SI) for mass is

telo118 [61]

The kilogram is the si

6 0

3 years ago

How many protons and electrons are present in Au+?

balandron [24]

Answer:

Protons: 79

Electrons: 78

Explanation:

1. The number of protons is the atomic number (The atomic number for Au on the periodic table is 79)

2. Since the charge is +1 (positive) it means that there's one more proton than electrons. So, 79-1 = 78 electrons

7 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.

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

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<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.

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

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<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.

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<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

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<h3>Answer:</h3>

We're provided with 20g of Calcium,

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

= 1 g H2

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Hope this helps!

6 0

2 years ago