Nguyên tử nguyên tố sắt có 26e<br> a. Viết cấu hình e của sắt<br> b. Sắt thuộc nguyên tố s,p,d,f

Ca(OH)2 + H2SO4 ⟶2H2O + CaSO4 What volume of 1.45 M Ca(OH)2 is needed to react with 25.0 moles of H2SO4?

Shkiper50 [21]

Answer:

We need 17.2 L of Ca(OH)2

Explanation:

Step 1: Data given

Concentration of Ca(OH)2 = 1.45 M

Moles of H2SO4 = 25.0 moles

Step 2: The balanced equation

Ca(OH)2 + H2SO4 ⟶2H2O + CaSO4

Step 3: Calculate moles Ca(OH)2

For 1 mol Ca(OH)2 we need 1 mol H2SO4 to produce 2 moles H2O and 1 mol CaSO4

For 25.0 moles H2SO4 we'll need 25.0 moles Ca(OH)2 to produce 50 moles H2O and 25.0 moles CaSO4

Step 4: Calculate volume of Ca(OH)2

Volume Ca(OH)2 = moles Ca(OH)2 / concentration Ca(OH)2

Volume Ca(OH)2 = 25.0 moles / 1.45 M

Volume Ca(OH)2 = 17.2 L

We need 17.2 L of Ca(OH)2

3 0

2 years ago

Rank these systems in order of decreasing entropy. 1 = Greatest entropy and 7 = Least entropy. Group of answer choices 1 mol of

AlladinOne [14]

Answer:

1 mole of carbon disulfide gas at 273 K and 40 L
1 mol of chlorine gas at 273 K and 40 L
1 mol of neon gas at 273 K and 40 L
1 mol of neon gas at 273 K and 20 L
1/2 mol of neon gas at 273 K and 20 L
1/2 mol of neon gas at 100 K and 20 L
1/2 mol of liquid neon at 100 K

Explanation:

Entropy is the measure of disorder or randomness in a closed system. Its an extensive property of a thermodynamic system

The following points must be considered when ranking the systems according to their entropy:

The entropy of gases are highest than liquids or solid. And entropy of liquid is higher than solid. That is because gas has more microstate thus have the highest entropy.
Entropies of large complicated molecules are greater than those of smaller, simpler molecules. Because larger molecules have more disorder because of the greater number of ways they can be move around in three dimensional space.
highest temperature and highest volume will lead to greatest entropy
1 mole of any substance will have greater entropy than 1/2 mole of that same substance

6 0

2 years ago

Whoever can answer these for me gets 100 points

tiny-mole [99]

Answer:

The electrons that whiz about outside the nucleus have a negative charge. They are held in the atom by the positive charge of the nucleus. ... An atom that gains or loses an electron becomes an ion. If it gains a negative electron, it becomes a negative ion.

Explanation:

Hope this helped!...

3 0

2 years ago

Read 2 more answers

Melissa's mother was making chocolate chip cookies, but told Melissa that she shouldn't eat the raw cookie dough. Why is it unsa

sashaice [31]

the answer to the question is D

4 0

3 years ago

Nicotine, a component of tobacco, is composed of C, H, and N. A 7.875-mg sample of nicotine was combusted, producing 21.363 mg o

Gnom [1K]

Answer: The empirical formula for the given compound is $C_5H_7N$

Explanation:

The chemical equation for the combustion of compound having carbon, hydrogen, and nitrogen follows:

$C_xH_yN_z+O_2\rightarrow CO_2+H_2O$

where, 'x', 'y' and 'z' are the subscripts of carbon, hydrogen and nitrogen respectively.

We are given:

Mass of $CO_2=21.363mg=21.363\times 10^3g=21363g$

Mass of $H_2O=6.125g=6.125\times 10^3g=6125g$

We know that:

Molar mass of carbon dioxide = 44 g/mol

Molar mass of water = 18 g/mol

For calculating the mass of carbon:

In 44 g of carbon dioxide, 12 g of carbon is contained.

So, in 21363 g of carbon dioxide, $\frac{12}{44}\times 21363=5826.27g$ of carbon will be contained.

For calculating the mass of hydrogen:

In 18 g of water, 2 g of hydrogen is contained.

So, in 6125 g of water, $\frac{2}{18}\times 6125=680.55$ of hydrogen will be contained.

Now we have to calculate the mass of nitrogen.

Mass of nitrogen in the compound = (7875) - (5826.27 + 680.55) = 1368.18 g

To formulate the empirical formula, we need to follow some steps:

Step 1: Converting the given masses into moles.

Moles of Carbon = $\frac{\text{Given mass of Carbon}}{\text{Molar mass of Carbon}}=\frac{5826.27g}{12g/mole}=485.52moles$

Moles of Hydrogen = $\frac{\text{Given mass of Hydrogen}}{\text{Molar mass of Hydrogen}}=\frac{680.55g}{1g/mole}=680.55moles$

Moles of Nitrogen = $\frac{\text{Given mass of nitrogen}}{\text{Molar mass of nitrogen}}=\frac{1368.18g}{14g/mole}=97.73moles$

Step 2: Calculating the mole ratio of the given elements.

For the mole ratio, we divide each value of the moles by the smallest number of moles calculated which is 0.0154 moles.

For Carbon = $\frac{485.52}{97.73}=4.96\approx 5$

For Hydrogen = $\frac{680.55}{97.73}=6.96\approx 7$

For Nitrogen = $\frac{97.73}{97.73}=1$

Step 3: Taking the mole ratio as their subscripts.

The ratio of C : H : N = 5 : 7 : 1

Hence, the empirical formula for the given compound nicotine is $C_5H_7N_1=C_5H_7N$

7 0

2 years ago

Nguyên tử nguyên tố sắt có 26e a. Viết cấu hình e của sắt b. Sắt thuộc nguyên tố s,p,d,f