Which atom has the smallest atomic radius between cesium, potassium, rubidium, and francium?

Name the SI base units that are important in chemistry, and give the SI units for expressing the following: (a)length, (b) volum

kirza4 [7]

Answer and Explanation:

The basic unit which are that are important in chemistry are meter, kilogram ,mol, $m^3$

Candela which is the unit of luminous of intensity is not so important in physics

(a) SI unit of length is meter (m)

(b) Si unit of volume is $m^3$

(c) Si unit of mass is kilogram (kg)

(d) SI unit of time is second (s)

(e) SI unit of temperature is kelvin (K)

4 0

2 years ago

By titration, it is found that 31.7 mL of 0.145 M NaOH(aq) is needed to neutralize 25.0 mL of HCl(aq). Calculate the concentrati

arlik [135]

Answer:

0.184 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 following data were obtained:

Mole ratio of the acid, HCl (nA) = 1

Mole ratio of the base, NaOH (nB) = 1

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

Volume of the base, NaOH (Vb) = 31.7 mL Molarity of the base, NaOH (Mb) = 0.145 M

Volume of the acid, HCl (Va) = 25.0 mL

Molarity of the acid, HCl (Ma) =?

Finally, we shall determine the molarity of the acid (HCl) as shown below:

MaVa /MbVb = nA/nB

Ma × 25 / 0.145 × 31.7 = 1

Cross multiply

Ma × 25 = 0.145 × 31.7

Ma × 25 = 4.5965

Divide both side by 25

Ma = 4.5965 / 25

Ma = 0.184 M

Therefore, the molarity of the acid (HCl) is 0.184 M

6 0

2 years ago

SCIENCE - Can someone tell me the ph level of rain water?

amid [387]

Normal rainwater has a pH of 5.6<span> (slightly acidic)</span>

8 0

2 years ago

Give the products of the reaction of butanal, with: (a) sodium borohydride, in methanol (b) hydrogen cyanide, with catalytic cya

miss Akunina [59]

Answer:

Answers are given below

Explanation:

(a) Aldehyde groups are reduced by sodium borohydride in methanol to give alcohol.

So, butanal produces butanol on reaction with sodium borohydride in methanol.

(b) Aldehyde forms cyanohydrin when they are treated with HCN with catalytic cyanide.

(c) Aldehydes are oxidized by potassium dichromate in dil. sulphuric acid to produce carboxylic acid.

(d) Aldehyde produces acetal with methanol and a trace amount of acid catalyst.

(e) Aldehyde gives condensation reaction with $CH_{3}CH_{2}NH_{2}$ to produce imine.

Structures of products for the given reaction has been shown below.

4 0

2 years ago

Which solution is a homogeneous mixture?

astra-53 [7]

Answer:

soil

Explanation:

4 0

2 years ago