Plz help for chemistry quiz I’ll mark brainliest

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.

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

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

<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

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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

_______________

Hope this helps!

6 0

2 years ago

What is the concentration of H+ ions at a pH = 11?

natta225 [31]

Answer:

$\huge 1 × {10}^{-11} \: \: M$

Explanation:

The pH of a solution can be found by using the formula

$pH = - log [ {H}^{+} ]$

Since we are finding the H+ ions we find the antilog of the pH

So we have

$11 = - log({H}^{+}) \\ {H}^{+} = {10}^{ - 11}$

We have the final answer as

$1 × {10}^{-11} \: \: M$

Hope this helps you

6 0

2 years ago

What is the mass of 3.75 moles of NaCI? ( Na= 22.99g/mol, CI= 35.45 g/mol)

seraphim [82]

Answer:

219.15 grams

Explanation:

What is the mass of 3.75 moles of NaCI? ( Na= 22.99g/mol, CI= 35.45 g/mol)

Mole of Na = 22.99g

Mole of Cl = 35.45g

For NaCl we have ratio of 1:1, so we have 1 Na for every Cl

So we just add the two together to get the molar mass of NaCl which is

22.99 + 35.45 = 58.44g/mol

And we know we have 3.75 moles of NaCl so we multiply that by the molar mass of NaCl to get our answer

3.75 x 58.44 = 219.15grams

6 0

3 years ago

I need help name the parts of making up the female part of the flower and state what each part does. ( answer in your own unique

nekit [7.7K]

<h2>Answer:-</h2>

The female part is the pistil. The pistil usually is located in the center of the flower and is made up of three parts: the stigma, style, and ovary. The stigma is the sticky knob at the top of the pistil. It is attached to the long, tube like structure called the style.

6 0

2 years ago

How many moles are in 2.372e+02 mg (milligrams) of bromic acid?

marishachu [46]

Answer:

1.840 x 10⁻³ mol HBrO₃

Explanation:

To find the moles of bromic acid (HBrO₃), you should (1) convert milligrams to grams (by dividing by 1,000) and then (2) convert moles to grams (via molar mass from periodic table).

Molar Mass (HBrO₃): 1.008 g/mol + 79.904 g/mol + 3(15.998 g/mol)

Molar Mass (HBrO₃): 128.906 g/mol

2.372 x 10² mg HBrO₃ 1 g 1 mole
---------------------------------x----------------x------------------ = 1.840 x 10⁻³ mol HBrO₃
1,000 mg 128.906 g

3 0

2 years ago