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3 years ago

Fill in the blanks with the correct words to complete the sentence.

Chemistry

1 answer:

navik [9.2K]3 years ago

4 0

Answer:

Explanation:

Salt water intrusion can cause the fresh water in wells to become contaminated with saltwater.

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Prepare indicators by using natural materials like extract of red cabbage leaves, crushed beetroot,

AysviL [449]

Answer:

ou have learnt in your previous classes that the sour and bitter

tastes of food are due to acids and bases, respectively, present in them.

If someone in the family is suffering from a problem of acidity after

overeating, which of the following would you suggest as a remedy– lemon

juice, vinegar or baking soda solution?

n Which property did you think of while choosing the remedy?

Surely you must have used your knowledge about the ability of

acids and bases to nullify each other’s effect.

n Recall how we tested sour and bitter substances without tasting

them.

You already know that acids are sour in taste and change the colour

of blue litmus to red, whereas, bases are bitter and change the colour of

the red litmus to blue. Litmus is a natural indicator, turmeric is another

such indicator. Have you noticed that a stain of curry on a white cloth

becomes reddish-brown when soap, which is basic in nature, is scrubbed

on it? It turns yellow again when the cloth is washed with plenty of

water. You can also use synthetic indicators such as methyl orange and

phenolphthalein to test for acids and bases.

In this Chapter, we will study the reactions of acids and bases, how

acids and bases cancel out each other’s effects and many more interesting

things that we use and see in our day-to-day life. Do You Know?

Litmus solution is a purple dye, which is extracted from lichen, a plant belonging to

the division Thallophyta, and is commonly used as an indicator. When the litmus

solution is neither acidic nor basic, its colour is purple. There are many other natural

materials like red cabbage leaves, turmeric, coloured petals of some flowers such as

Hydrangea, Petunia and Geranium, which indicate the presence of acid or base in a

solution. These are called acid-base indicators or sometimes simply indicators.

2021–22

18 Science

2.1 UNDERSTANDING THE CHEMICAL PROPERTIES OF

ACIDS AND BASES

2.1.1 Acids and Bases in the Laboratory

Activity 2.1

These indicators tell us whether a substance is acidic or basic by

change in colour. There are some substances whose odour changes in

acidic or basic media. These are called olfactory indicators. Let us try

out some of these indicators.

Explanation:

8 0

3 years ago

As the density of a substance decreases, the volume of a given mass of that substance ______.

Brilliant_brown [7]

The answer to your question is,

D. Fluctuates

-Mabel <3

7 0

4 years ago

Read 2 more answers

Calculate the pH of the resulting solution if 32.0 mL of 0.320 M HCl(aq) is added to (a) 42.0 mL of 0.320 M NaOH(aq). (b) 22.0 m

monitta

Answer:

a) pH = 11.5

b) pH= 3

Explanation:

a) lets calculate the number of moles of each reactant

moles of HCl = 32/1000 * 0.32 = 0.01024 mole

moles of NaOH = 42/1000 * 0.32 = 0.01344 moles

1 moles of HCl reacts with 1 moles of NaOH , so 0.01024 mole of HCl should react with 0.01024 moles of NaOH , but there is some excess NaOH.

excess NaOH= 0.01344 -0.01024 = 0.0032 moles

[H+]= $\frac{10^{-14} }{0.0032} = 3.125 *10^{-12}$

pH= -log [3.125*10^-12) = 11.5

b) moles of NaOH = 0.00924

excess HCl present = 0.01024 - 0.00924 =.001

so excess [H+] = 0.001

pH= -log( 0.001) = 3

3 0

3 years ago

A key step in the extraction of iron from its ore is FeO(s) + CO(g) ⇋ Fe(s) + CO2(g) Kp =0.403 at 1000°C. What are the equilibri

andriy [413]

Answer:

0.713atm for CO and 0.287atm for CO₂

Explanation:

Based on the reaction:

FeO(s) + CO(g) ⇋ Fe(s) + CO₂(g)

Kp is defined as:

$Kp = \frac{P_{CO_2}}{P_{CO}}$ = 0.403

When 1.00 atm of CO react with an excess of FeO, the pressures in equilibrium are:

PCO = 1.00atm - x

PCO₂ = x

Where x represents the reaction coordinate.

Replacing in Kp expression:

$0.403 = \frac{x}{1-x}$

0.403 - 0.403x = x

0.403 = 1.403x

0.287atm = x

Thus, pressures in equilibrium are:

PCO = 1.00atm - x = 0.713atm

PCO₂ = x = 0.287atm

8 0

3 years ago

Using the thermodynamic information in the ALEKS Data tab, calculate the standard reaction free energy of the following chemical

Svetlanka [38]

Answer:

mermaid bajuo mein going to read I chapter call sleepy Harry now we started sleepy Harry was born on 23 September 1783 in London London England the popular rhymes twinkle twinkle little Star poem and stories just let them who does not want to go to sleep you wanted to continue playing but I want him to go to but because it is late read on to now that happens sleepy Hari I am going to start now thatand all of what is his as if his calls be there with you must come and at the best and to get them go to roast went there short and all the duck and goose you know them went to bed and Harry so I am going to say the meaning off place where a place where birds and first means a bird that accident

4 0

3 years ago