URGENT HELP PLEASE balance equation !20 points!

Click on the question mark. Choose the MOST reasonable inference based on the text evidence and what you already know. "in a anc

katrin2010 [14]

Answer:

in an ancient

Explanation:

when the word begins with a vowel you say an instead of a

8 0

3 years ago

Match the term with its description.

blagie [28]

Answer:

Pure substance B) Consists of a single element or type of compound.

Homogeneous A) Mixture that has its different components mixed evenly within the substance.

Heterogeneous D) Mixture that has its different components mixed unevenly within the substance.

Solution C) Liquid homogeneous mixture in which the solute is distributed evenly within the solvent.

Explanation:

Pure substances are a form of matter with definite constant composition and distinct properties. They consist of a single element or type of compound, as can be seen in its formula. Na, O₂, NaCl and H₂O are examples of pure substances.

When 2 or more pure substances are mixed together they form a mixture. If the mixture has its different components mixed <u>evenly</u> within the substance it is a homogeneous mixture. Whereas if the mixture has its different components mixed <u>unevenly</u> within the substance it is a heterogeneous mixture. The different parts observable in a heterogeneous mixture are known as phases.

In liquid homogeneous mixtures, we can recognize one or more substances that are in lower proportions (solutes) and one substance that is in greater proportion (solvent). This kind of mixture is known as a solution.

3 0

3 years ago

Baking soda NaHCO3, is made from soda ash, a common name for sodium carbonate. The soda ash is obtained in two ways. It can be m

Vaselesa [24]

Answer:

Explanation:

From the given information:

mass of silver chloride AgCl = 11.89 g

molar mass of AgCl = 143.37 g/mol

We know that:

number of moles = mass/molar mass

∴

number of moles of AgCl = 11.89 g/ 143.37 g/mol

number of moles of AgCl = 0.0829 mol

The chemical equation for the mineral called trona is:

$\mathsf{Na_2CO_3.NaHCO_3.2H_2O}$

when being reacted with hydrochloric acid, we have:

$\mathsf{Na_2CO_3.NaHCO_3.2H_2O + 3HCl \to 3NaCl + 2CO_2 +4H_2O}$

One mole of NaCl formed from one mole of trona sample = 0.0829 moles of AgCl

i.e. 0.0829 moles of NaCl can be formed from AgCl

mass of trona sample = number of moles × molar mass

mass of trona sample = 0.0829 × 226

mass of trona sample = 18.735 g

The mass in the percentage of NaHCO₃ = mass of NaHCO₃/ mass of trona

The mass in the percentage of NaHCO₃ = 6.93/18.735

The mass in the percentage of NaHCO₃ = 0.36989

The mass in the percentage of NaHCO₃ = 36.99%

Nonetheless, a 6.78 g samples manufactured from sodium carbonate in pure 100%

∴

6.78 g sample manufactured from Na₂CO₃ is purer.

8 0

3 years ago

A plastic bottle is closed outdoors on a cold day when the temperature is −15.0°C and is later brought inside where the temperat

Lana71 [14]

Answer:

Pressure = 1.14 atm

Explanation:

Hello,

This question requires us to calculate the final pressure of the bottle after thermal equilibrium.

This is a direct application of pressure law which states that in a fixed mass of gas, the pressure of a given gas is directly proportional to its temperature, provided that volume remains constant.

Mathematically, what this implies is

P = kT k = P / T

P1 / T1 = P2 / T2 = P3 / T3 =........= Pn / Tn

P1 / T1 = P2 / T2

P1 = 1.0atm

T1 = -15°C = (-15 + 273.15)K = 258.15K

P2 = ?

T2 = 21.5°C = (21.5 + 273.15)K = 294.65K

P1 / T1 = P2 / T2

P2 = (P1 × T2) / T1

P2 = (1.0 × 294.65) / 258.15

P2 = 1.14atm

The pressure of the gas after attaining equilibrium is 1.14atm

3 0

3 years ago

An air mass usually forms in an area of _____. low pressure because it's stable low pressure because it's unstable high pressure

horsena [70]

Answer: high pressure because it's stable

Explanation:

Air mass is volume of air which has stable temperature, humidity and pressure horizontally. Over time, each air mass acquires properties of the region by residing over same part of a surface.

Areas of low pressure and high pressure occur where there is warm air and cold air respectively. An air mass usually forms over an area of high pressure. Warm air rises up and cold air takes its place. Warm air has low density and low pressure where as cold air has high density and pressure and therefore, sinks to the bottom. This is a stable condition. The movement of air mass is responsible for maintenance of temperature conditions on Earth.

6 0

3 years ago