While the number nuclear protons as given is 34, and therefore we deal with the element selenium, there are 2 more electrons than protons, and therefore this species has an overall
2
−
charge.
We represent this selenide ion as
S
e
2
−
. Do I win 5 pounds?

Z= 34, therefore the atom is selenium

7 0

3 years ago

You are given a solution of HCOOH (formic acid) with an approximate concentration of 0.20 M and you will titrate this with a 0.1

jeka57 [31]

Answer:

$\boxed{\text{36 mL}}$

Explanation:

1. Write the balanced chemical equation.

$\rm HCOOH + NaOH $ \longrightarrow$ HCOONa + H$_{2}$O$

2. Calculate the moles of HCOOH

$\text{Moles of HCOOH} =\text{20.00 mL HCOOH } \times \dfrac{\text{0.20 mmol HCOOHl}}{\text{1 mL HCOOH}} = \text{4.00 mmol HCOOH}$

3. Calculate the moles of NaOH.

$\text{Moles of NaOH = 4.00 mmol HCOOH } \times \dfrac{\text{1 mmol NaOH} }{\text{1 mmol HCOOH}} = \text{4.00 mmol NaOH}$

4. Calculate the volume of NaOH

$c = \text{4.00 mmol NaOH } \times \dfrac{\text{1 mL NaOH }}{\text{0.1105 mmol NaOH }} = \textbf{36 mL NaOH }\\\\\text{The titration will require }\boxed{\textbf{36 mL of NaOH}}$

3 0

3 years ago

What is osmotic pressure of a solution that contains 13.7 g of propyl alcohol (C3H7OH) dissolved in enough water to make 500 mL

azamat

Answer:

Π = iMRT ½

Explanation:

111 g

= 0.033 mol

0.033 mol CaCl2

0.09632 kg solvent

= 0.0344 m

13.7 g x 1 mol C3H7OH

60.10 g

0.5 L

(0.0821 L.atm/K.mol) (300.15K

4 0

4 years ago

Arrange the following atoms in order of decreasing atomic radius

ElenaW [278]

Answer:

............. ..

6 0

3 years ago

The outermost shell of an atom in known as ??​

The outermost shell of an atom in known as ??