You have a 55 mL of a 4.3 M solution of CaCl, and you add 100. mL to it. What is the

Which statement describes a process involved in the evolution of Earth’s early atmosphere?

yan [13]

Answer:

The statement describes a process involved in the evolution of Earth’s early atmosphere would be:

Cyanobacteria transformed carbon dioxide in the atmosphere into oxygen during photosynthesis

Hope it helped :3

4 0

3 years ago

Estradiol is a female sexual hormone that causes maturation and maintenance of the female reproductive system. Elemental analysi

Ipatiy [6.2K]

Answer:

The molecular formula of estradiol is: $C_{18}H_{24}O_2$ .

Explanation:

Molar mass of of estradiol = M= 272.37 g/mol

Let the molecular formula of estradiol be $C_xH_yO_z$

Percentage of an element in a compound:

$\frac{\text{Number of atoms of element}\times \text{Atomic mass of element}}{\text{molecular mass of element}}\times 100$

Percentage of carbon in estradiol :

$\frac{x\times 12 g/mol}{272.37 g/mol}\times 100=79.37\%$

x = 18.0

Percentage of hydrogen in estradiol :

$\frac{y\times 1g/mol}{272.37 g/mol}\times 100=8.88\%$

y = 24.2 ≈ 24

Percentage of oxygen in estradiol :

$\frac{z\times 16 g/mol}{272.37 g/mol}\times 100=11.75\%$

z = 2

The molecular formula of estradiol is: $C_xH_yO_z:C_{18}H_{24}O_2$

7 0

2 years ago

A. How many protons, electrons, and neutrons make up an atom

mestny [16]

Answer:

45 neutrons

Explanation:

Bromine has 35 protons and a mass number of 80. a) How many neutrons does the atom of bromine have? The mass number = protons + neutrons. Bromine has a mass number of 80 and 35 protons so 80-35 = 45 neutrons.

5 0

1 year ago

The pH of a 1.0M solution of butanoic acid HC4H7O2 is measured to be 2.41. Calculate the acid dissociation constant Ka of butano

Lubov Fominskaja [6]

Answer:

Ka = 1.52 E-5

Explanation:

CH3-(CH2)2-COOH ↔ CH3(CH2)2COO- + H3O+

⇒ Ka = [H3O+][CH3)CH2)2COO-] / [CH3(CH2)2COOH]

mass balance:

⇒<em> C</em> CH3(CH2)2COOH = [CH3(CH2)2COO-] + [CH3(CH2)2COOH] = 1.0 M

charge balance:

⇒ [H3O+] = [CH3(CH2)2COO-]

⇒ Ka = [H3O+]²/(1 - [H3O+])

∴ pH = 2.41 = - Log [H3O+]

⇒ [H3O+] = 3.89 E-3 M

⇒ Ka = (3.89 E-3)² / ( 1 - 3.89 E-3 )

⇒ Ka = 1.519 E-5

3 0

3 years ago

Please help, with step by step work

natali 33 [55]

$\qquad$ ☀️ $\pink{\bf{ {Answer = \: \: 85.57g }}}$

Molar mass of $\bf Cu_2O$

$\qquad$ $\twoheadrightarrow\sf 63.546 \times 2 +16$

$\qquad$ $\pink{\twoheadrightarrow\bf 143.092 g}$

<u>As we know</u>–

1 mol = $\bf 6.02×10^{23}$ formula units

1 mol $\bf Cu_2O$ = 143.092 g = $\bf 6.02×10^{23}$ formula units

Henceforth –

$\bf 3.60×10^{23}$ formula units $\bf Cu_2O$ –

$\qquad$ $\sf :\implies \dfrac{143.092 \times3.60×10^{23 }}{6.02×10^{23}}$

$\qquad$ $\sf :\implies \dfrac{143.092 \times3.60×\cancel{10^{23 }}}{6.02×\cancel{10^{23}}}$

$\qquad$ $\pink{:\implies\bf 85.57 g}$

5 0

2 years ago