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Why is it important that there is only a small amount of water in the beaker

natita [175]

Answer:

because too much can neutralise the results

4 0

3 years ago

Read 2 more answers

Polymer formed from methylene diphenyl isocyanate

marin [14]

Answer:

Polymeric MDI is a mixture of. monomeric MDI as well as larger molecular weight oligomers of MDI, and is a brownish. liquid at room temperature and may have a slight odor. Commercial MDI products are. often mixtures of monomeric and polymeric MDI and can contain other additives as well.

Explanation:

5 0

3 years ago

A solution of hydrochloric acid (HCl, 25.00 mL) was titrated to completion with 34.55 mL of 0.1020 M sodium hydroxide. What was

kati45 [8]

Answer:

0.1410 M

Explanation:

We'll begin by writing the balanced equation for the reaction. This is illustrated below:

HCl + NaOH —> NaCl + H₂O

From the balanced equation above,

The mole ratio of the acid, HCl (nA) = 1

The mole ratio of the base, NaOH (nB) = 1

Next, the data obtained from the question. This include:

Volume of acid, HCl (Va) = 25 mL

Volume of base, NaOH (Vb) = 34.55 mL

Concentration of base, NaOH (Cb) = 0.1020 M

Concentration of acid, HCl (Ca) =?

CaVa / CbVb = nA/nB

Ca × 25 / 0.1020 × 34.55 = 1/1

Ca × 25 / 3.5241 = 1/1

Cross multiply

Ca × 25 = 3.5241 × 1

Ca × 25 = 3.5241

Divide both side by 25

Ca = 3.5241 / 25

Ca = 0.1410 M

Therefore, the concentration of the acid, HCl is 0.1410 M

3 0

3 years ago

When 0.620 gMngMn is combined with enough hydrochloric acid to make 100.0 mLmL of solution in a coffee-cup calorimeter, all of t

OleMash [197]

Answer:

The enthalpy change during the reaction is -199. kJ/mol.

Explanation:

$Mn(s)+2HCl(aq)\rightarrow MnCl_2(aq)+H_2(g)$

Mass of solution = m

Volume of solution = 100.0 mL

Density of solution = d = 1.00 g/mL

$m=1.00 g/mL\times 100.0 mL = 100 g$

First we have to calculate the heat gained by the solution in coffee-cup calorimeter.

$q=m\times c\times (T_{final}-T_{initial})$

where,

m = mass of solution = 100 g

q = heat gained = ?

c = specific heat = $4.18 J/^oC$

$T_{final}$ = final temperature = $23.1^oC$

$T_{initial}$ = initial temperature = $28.9^oC$

Now put all the given values in the above formula, we get:

$q=100 g \times 4.18 J/^oC\times (28.9-23.1)^oC$

$q=2,242.4 J=2.242 kJ$

Now we have to calculate the enthalpy change during the reaction.

$\Delta H=-\frac{q}{n}$

where,

$\Delta H$ = enthalpy change = ?

q = heat gained = 2.242 kJ

n = number of moles fructose = $\frac{\text{Mass of manganese}}{\text{Molar mass of manganese}}=\frac{0.620 g}{54.94 g/mol}=0.0113 mol$

$\Delta H=-\frac{2.242 kJ}{0.0113 mol }=-199. kJ/mol$

Therefore, the enthalpy change during the reaction is -199. kJ/mol.

8 0

2 years ago

Give all possible ml values for orbitals that have each of the following:<br> (a) l = 3;

Angelina_Jolie [31]

At l = 3, ml =+3,+2,+1,0,-1,-2,-3

What are quantum numbers?

Quantum numbers are used to describe where around a nucleus a particular electron can be found.
In any given atom, each electron can be described by four quantum numbers.
These are n,l,m1,ms
The values that each number can be are based on a set of rules.

What is a magnetic quantum number ?

It describes the orientation of the orbitals.
It is represented as ml.
The value of this quantum number ranges from (-l to +l).
When l = 2, the value of will be -2, -1, 0, +1, +2.

To know more about magnetic quantum numbers, refer:

brainly.com/question/14650566

#SPJ4

8 0

1 year ago