What was the process that Marie curie used to turn 8 tons of rubble into 1/5 of a teaspoon of radium?

150 ml of 0.1 m naoh is added to 200 ml of 0.1 m formic acid, and water is added to give a final volume of 1 l. what is the ph o

N76 [4]

Number of moles of NaOH = V(NaOH) * M(NaOH)= 0.150 L * 0.1 moles/L = 0.015 moles

Number of moles of formic acid, HCOOH = V(HCOOH) * M(HCOOH) = 0.200 L * 0.1 moles/L = 0.020 moles

Here, the limiting reagent is NaOH

The reaction is represented as:

HCOOH + NaOH ↔HCOONa + H2O

Moles of HCOONa formed = Moles of the limiting reagent, NaOH = 0.015 moles

Moles of HCOOH remaining = 0.020-0.015 = 0.005 moles

Total final volume is given as 1 L

Therefore: [HCOOH] = 0.005 moles/1 L = 0.005 M

[HCOONa] = 0.015/1 = 0.015 M

pKa of HCOOH = 3.74

As per Henderson-Hasselbalch equation

pH = pka + log[HCOONa]/[HCOOH] = 3.74+log[0.015/0.005] = 4.22

Therefore, pH of the final solution = 4.22

3 0

3 years ago

_____Mg + ____Fe2O3 → _____Fe + ____MgO

german

Answer:

3Mg + Fe₂O₃ → 2 Fe + 3MgO

Explanation:

Chemical equation;

Mg + Fe₂O₃ → Fe + MgO

Balanced Chemical equation;

3Mg + Fe₂O₃ → 2Fe + 3MgO

This is the balanced equation. There are three magnesium, two iron and three oxygen atoms are on both side of equation thus it follow the law of conservation of mass.

Law of conservation of mass:

According to the law of conservation mass, mass can neither be created nor destroyed in a chemical equation.

This law was given by french chemist Antoine Lavoisier in 1789. According to this law mass of reactant and mass of product must be equal, because masses are not created or destroyed in a chemical reaction.

7 0

3 years ago

How many grams of h2 will be produced if 175g of HCI are allowed to react completely with sodium

Sedbober [7]

Answer:

4.8 grams of H₂ will be produced if 175g of HCI are allowed to react completely with sodium

Explanation:

By stoichiometry of the reaction (that is, the relationship between the amount of reagents and products in a chemical reaction) you can see that the following amounts in moles of each compound react and are produced:

HCl: 2 moles
Na: 1 mole
NaCl: 2 moles
H₂: 1 mole

You know the following masses of each element:

H: 1 g/mole
Cl: 35.45 g/mole
Na: 23 g/mole

So, the molar mass of each compound participating in the reaction is:

HCl: 1 g/mole + 35.45 g/mole= 36.45 g/mole
Na: 23 g/mole
NaCl: 23 g/mole + 35.45 g/mole= 58.45 g/mole
H₂: 2* 1 g/mole= 2 g/mole

Then, by stoichiometry of the reaction, the following amounts in grams of each of the compounds participating in the reaction react and are produced:

HCl: 2 moles* 36.45 g/mole= 72.9 g
Na: 1 mole* 23 g/mole= 23 g
NaCl: 2 moles* 58.45 g/mole= 116.9 g
H₂: 1 mole* 2 g/mole= 2 g

So, a rule of three applies as follows: if by stoichiometry, when reacting 72.9 grams of HCl 2 grams of H₂ are formed, when reacting 175 grams of HCl how much mass of H₂ will be formed?

$mass of H_{2} =\frac{175 g of HCl*2g ofH_{2} }{72.9 g of HCl}$

mass of H₂= 4.8 g

<u><em>4.8 grams of H₂ will be produced if 175g of HCI are allowed to react completely with sodium</em></u>

3 0

2 years ago

Read 2 more answers

Write an equation that shows the formation of the chloride ion from a neutral chlorine atom

jeka57 [31]

The gaining of electron by an atom results in the formation of anion shown by the negative charge on the atom whereas lose of electron results in the formation of cation shown by positive charge on the atom. The atom lose or gain electron to complete their octet and get stable in nature.

The chlorine atom will gain an electron and form chloride anion with one negative charge on it. The chloride ion is more stable in nature compared to the chlorine atom due to complete octet of chloride ion by gaining of electron.

Electronic configuration of chlorine atom is:

$[Ne]3s^{2}3p^{5}$

By gaining of one electron, electronic configuration of chloride ion is:

$[Ne]3s^{2}3p^{6}$

Thus, the equation that shows the formation of the chloride ion from a neutral chlorine atom is:

$Cl+1e^{-}\rightarrow Cl^{-}$

4 0

3 years ago

How do balanced chemical equations show the conservation of mass

antiseptic1488 [7]

Answer: Matter cannot be created or destroyed

Explanation: Balanced equations are set equations we cannot change one element or compound in the equation without changing the entire equation. So balanced equation show the conservation of mass because while other substances may be formed from the synthesis or decomposition of compounds new elements are never introduced and are not created out of thin air :)

4 0

2 years ago

Read 2 more answers