The number placed in front of a compound to balance a chemical reaction is called?

Define international system of units , where does the system originate

BARSIC [14]

Answer:

The International System of Units (SI) is originated in France by frenches and originally was called a metric system of measurements. It provides definitions of various units of measurement such as weight, distance, electric current, temperature, and others which is widely accepted in the different fields of science and technology.

It is the system that is extended and derived from the french metric system of measurement is accepted in 1960 by convention 44 nation of the world to use particular unit of measurement worldwide to avoid confusion.

6 0

2 years ago

Karen has a mass of 53 kg as she rides the up escalator at woodley park station of the washington

aivan3 [116]

Vertical height of longest escalator in free world = 58.8 sin 32.4 = 31. 5 m
Karen's mass = 54.6 kg
Work done on Karen = mgh = 54.6(9.81)(31.5) = 1.69e4 J = 16.9 KJ ANS

7 0

3 years ago

__ SnCl4 → __ Sn + __ Cl2

Kisachek [45]

Answer:

Sn (s) + 2 Cl2 (g) → SnCl4 (l)

This is an oxidation-reduction (redox) reaction:

4 Cl0 + 4 e- → 4 Cl-I

(reduction)

Sn0 - 4 e- → SnIV

(oxidation)

Cl2 is an oxidizing agent, Sn is a reducing agent.

Reactants:

Sn

Names: Tin source: wikidata, accessed: 2019-09-07source: ICSC, accessed: 2019-09-04source: NIOSH NPG, accessed: 2019-09-02, Sn source: wikidata, accessed: 2019-09-07, Element 50 source: wikidata, accessed: 2019-09-07

Appearance: White crystalline powder source: ICSC, accessed: 2019-09-04; Gray to almost silver-white, ductile, malleable, lustrous solid. source: NIOSH NPG, accessed: 2019-09-02

Cl2

Names: Chlorine source: ICSC, accessed: 2019-09-04source: NIOSH NPG, accessed: 2019-09-02, Molecular chlorine source: NIOSH NPG, accessed: 2019-09-02

Appearance: Greenish-yellow compressed liquefied gas with pungent odour source: ICSC, accessed: 2019-09-04; Greenish-yellow gas with a pungent, irritating odor. [Note: Shipped as a liquefied compressed gas.] source: NIOSH NPG, accessed: 2019-09-02

Products:

SnCl4 – Tetrachlorostannane source: wikipedia, accessed: 2019-09-28source: wikidata, accessed: 2019-09-02, Tin tetrachloride source: wikipedia, accessed: 2019-09-28source: wikidata, accessed: 2019-09-02source: ICSC, accessed: 2019-09-04, Tin(IV) chloride source: wikipedia, accessed: 2019-09-28

Other names: Stannic chloride source: wikipedia, accessed: 2019-09-28source: wikidata, accessed: 2019-09-02source: ICSC, accessed: 2019-09-04, Tin(iv) chloride (anhydrous) source: ICSC, accessed: 2019-09-04

Appearance: Colorless to slightly yellow fuming liquid source: wikipedia, accessed: 2019-09-28; Colourless or slightly yellow fuming liquid with pungent odour source: ICSC, accessed: 2019-09-04

6 0

2 years ago

WORD BANK:

ella [17]

Answer:

hot, less, rise, top, cold, closer, more, sink

Explanation:

I'm in high-school done this long time ago

3 0

2 years ago

Read 2 more answers

18. Suggest an explanation for the observations that ethanol, C2H5OH, is completely miscible with water and that ethanethiol, C2

nydimaria [60]

Answer:

Ethanol is completely miscible due to presence of Hydrogen bonding.

Ethanethiol is partially miscible due to absence of Hydrogen Bonding.

Explanation:

The miscibility of liquids depend upon the intermolecular interactions between the two liquids. The stronger the intermolecular interactions the more miscible will be the liquids.

Among the two given examples, Ethanol is more miscible in water because it exhibits hydrogen bonding which is considered the strongest intermolecular interaction. Hydrogen bonding occurs when the hydrogen atom is bonded to more electronegative atoms like Fluorine, Oxygen and Nitrogen. In this way the hydrogen atom gets partial positive charge and the electronegative atom gets partial negative charge. Hence, these partial charges results in attracting the opposite charges on other surrounding atoms.

While, in case of Ethanethiol the hydrogen atom is not bonded to any high electronegative atom hence, there will be no hydrogen bonding and therefore, there will be less interactions between the neighbour atoms.

6 0

3 years ago