Which member of each of the following pairs would you expect to have the higher melting point? Explain your reasoning. (1 each)

Name a machine used to reap, thresh and clean the crop. i will give brainliest who answers first

meriva

Answer:

combine harvester, or a combiner.

4 0

2 years ago

How many grams of sodium acetate ( molar mass = 83.06 g/mol ) must be added to 1.00 Liter of a 0.200 M acetic acid solution to m

Pie

Answer: The mass of sodium acetate that must be added is 30.23 grams

Explanation:

To calculate the number of moles for given molarity, we use the equation:

$\text{Molarity of the solution}=\frac{\text{Moles of solute}}{\text{Volume of solution (in L)}}$

Molarity of acetic acid solution = 0.200 M

Volume of solution = 1 L

Putting values in above equation, we get:

$0.200M=\frac{\text{Moles of acetic acid}}{1L}\\\\\text{Moles of acetic acid}=(0.200mol/L\times 1L)=0.200mol$

To calculate the pH of acidic buffer, we use the equation given by Henderson Hasselbalch:

$pH=pK_a+\log(\frac{[\text{salt}]}{[\text{acid}]})$

$pH=pK_a+\log(\frac{[CH_3COONa]}{[CH_3COOH]})$

We are given:

$pK_a$ = negative logarithm of acid dissociation constant of acetic acid = 4.74

$[CH_3COONa]=?mol$

$[CH_3COOH]=0.200mol$

pH = 5.00

Putting values in above equation, we get:

$5=4.74+\log(\frac{[CH_3COONa]}{0.200})$

$[CH_3COONa]=0.364mol$

To calculate the mass of sodium acetate for given number of moles, we use the equation:

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$

Molar mass of sodium acetate = 83.06 g/mol

Moles of sodium acetate = 0.364 moles

Putting values in above equation, we get:

$0.364mol=\frac{\text{Mass of sodium acetate}}{83.06g/mol}\\\\\text{Mass of sodium acetate}=(0.364mol\times 83.06g/mol)=30.23g$

Hence, the mass of sodium acetate that must be added is 30.23 grams

7 0

3 years ago

How many moles of a gas would occupy 22.4 Liters at 273 K and 1 atm?

Molodets [167]

Answer:

1 mole of a gas would occupy 22.4 Liters at 273 K and 1 atm

Explanation:

An ideal gas is a set of atoms or molecules that move freely without interactions. The pressure exerted by the gas is due to the collisions of the molecules with the walls of the container. The ideal gas behavior is at low pressures, that is, at the limit of zero density. At high pressures the molecules interact and intermolecular forces cause the gas to deviate from ideality.

An ideal gas is characterized by three state variables: absolute pressure (P), volume (V), and absolute temperature (T). The relationship between them constitutes the ideal gas law, an equation that relates the three variables if the amount of substance, number of moles n, remains constant and where R is the molar constant of the gases:

P * V = n * R * T

In this case:

P= 1 atm
V= 22.4 L
n= ?
R= 0.082 $\frac{atm*L}{mol*K}$
T=273 K

Reemplacing:

1 atm* 22.4 L= n* 0.082 $\frac{atm*L}{mol*K}$ *273 K

Solving:

$n=\frac{1 atm* 22.4 L}{0.082 \frac{atm*L}{mol*K} *273 K}$

n= 1 mol

Another way to get the same result is by taking the STP conditions into account.

The STP conditions refer to the standard temperature and pressure. Pressure values at 1 atmosphere and temperature at 0 ° C (or 273 K) are used and are reference values for gases. And in these conditions 1 mole of any gas occupies an approximate volume of 22.4 liters.

1 mole of a gas would occupy 22.4 Liters at 273 K and 1 atm

4 0

2 years ago

What are uses of metals??

blondinia [14]

Answer:

Different uses of Metals

Metals are usually very strong, most durable and highly resistant to everyday wear and tear. As such, they have been used since ancient times for a lot of things. And even today with advances in technology and a lot of other things the uses of metals have broadened greatly. Metals even play a key role in the economy. Let’s look at some important and popular metals uses.

In the Construction Industry

In electronics

In medicine

Machinery, Refractory and Automobiles

Decorative products

Other Uses

In the Construction Industry

Metals are the main component in the construction industry. Metals like iron, steel amongst others are the main materials used in construction of buildings and even homes.

In Electronics

Another important application of metals are in electronics. As metals are good conductors of electricity, they are used to making wires and parts for equipments and gadgets that function on electrical current. Popular examples include, TV, mobiles, fridge, iron, computers etc.

In medicine

If you are wondering how, well from a biological perspective metals are found as micro-elements in our bodies. Besides, the presence of metal elements is crucial for several functions like transmission of nerve impulses, oxygen flow, reaction between enzymes etc. Some medicines are therefore liaised with metal compounds to treat certain deficiencies or sickness. Metals like, iron, calcium, magnesium, potassium titanium, and aluminum are used commonly in medicine in the form of antacids.

Apart from this, most of the equipments and tools used are made from metals.

Machinery, Refractory and Automobiles

This is one of the most common use of metals. They are used extensively in manufacturing machines for industries, agriculture or farming and automobiles which include road vehicles, railways, airplanes, rockets etc. Here, the commonly used metals are iron, aluminum and steel.

Besides these, most of the utensils that is used in the kitchen are made from metals like steel, aluminum, and copper. Due to a high temperature withstanding nature metals are preferred the most.

Decorative products

Metals such as platinum, gold, and silver come under the category of precious metals and have high economical value. These metals are widely used in making jewellery sets or for some decorative piece.

Other Uses of Metals

Some other uses and applications of metals are, they play an important role in security as the metals are used in making locks, strong safe, doors etc. Apart from this, furnitures are made from metal these days. Metals also find their uses in the military where they are used to manufacturing weapons and ammunitions. Some metals are used in galvanizing to protect from rusting.

These are some popular uses of metal. To know more about metals, different types, properties of metals and more you can keep visiting BYJU’S or you can also download our app for interesting content and learning experience

3 0

3 years ago

A chemist mixes 1.00 g CuCl2 with an excess of (NH4)2HPO4 in dilute aqueous solution . He measures the evolution of 670 J of hea

kaheart [24]

Answer:

$\Delta H$ will be 90054 J