What type of a reaction occurs when potassium metal reacts with fluorine gas?

A 31.5 g wafer of pure gold initially at 69.4 ∘C is submerged into 63.4 g of water at 27.4 ∘C in an insulated container.

liubo4ka [24]

Answer: The final temperature of both substances at thermal equilibrium is 301.0 K

Explanation:

$heat_{absorbed}=heat_{released}$

As we know that,

$Q=m\times c\times \Delta T=m\times c\times (T_{final}-T_{initial})$

$m_1\times c_1\times (T_{final}-T_1)=-[m_2\times c_2\times (T_{final}-T_2)]$ .................(1)

where,

q = heat absorbed or released

$m_1$ = mass of gold = 31.5 g

$m_2$ = mass of water = 63.4 g

$T_{final}$ = final temperature = ?

$T_1$ = temperature of gold = $69.4^oC=342.4K$

$T_2$ = temperature of water = $27.4^oC=300.4K$

$c_1$ = specific heat of gold = $0.129J/g^0C$

$c_2$ = specific heat of water= $4.184J/g^0C$

Now put all the given values in equation (1), we get

$-31.5\times 0.129\times (T_{final}-342.4)=[63.4\times 4.184\times (T_{final}-300.4)]$

$T_{final}=301.0K$

The final temperature of both substances at thermal equilibrium is 301.0 K

4 0

4 years ago

Natural disasters can cause both immediate and long-term issues. For example, flooding is an immediate threat with dangerous hig

GalinKa [24]

Answer:

. B. The boxes must minimize thermal energy transfer to prevent thermal energy from transferring into the boxes.

Explanation:

If a box is to remain cool, energy transfer into the box must be minimized and energy transfer out of the box must be maximized.

This implies that only a minimal amount of thermal energy can transfer into the box while the box looses heat rapidly. If a box is this designed, it is likely to remain cool.

3 0

3 years ago

I NEED HELP!!

solmaris [256]

A simple sugars are formed

5 0

3 years ago

Read 2 more answers

How many molecules of sodium oxide will be created if 275 grams of sodium reacts with excess oxygen?

DaniilM [7]

Answer:

1.34 × 10²⁴ molecules

Explanation:

To calculate the number of molecules of sodium oxide that will be created if 275 grams of sodium reacts with excess oxygen, use the chemical equation to calculate the number of moles and then multiply by Avogadro's number.

1) Balanced chemical equation (given):

4Na + O₂ → 2Na₂O

2) Mole ratio:

4 mol Na : 2 mol Na₂O

3) Calculate the number of moles in 275 g of Na:

n = mass in grams / molar mass
mass of Na = 275 g
molar mass of Na₂O = 61.9789 g/mol

n = 275 g / 61.9789 g/mol = 4.437 mol of Na

4) Set a proportion to find the number of moles of product (Na₂O):

2 mol Na₂O / 4 mol Na = x / 4.437 mol Na

x = 4.437 / 2 mol Na₂O = 2.2185 mol Na₂O

5) Convert the number of moles to number of molecules:

# molecules = n × 6.022 × 10²³ molecules/mol = 2.2185 mol × 6.022 × 10²³ molecules/mol = 1.34 × 10²⁴ molecules (rounded to 3 significant figures).

6 0

3 years ago

Assume you do not know which peak in GC chromatogram corresponds to each alkene (and you are not sure whether the one with lower

Zinaida [17]

GC chromatograms often already have a library of compounds to determine what the substance is. In case the compound cannot be found in the library, one common alternative scientists use when performing is spiking.

Spiking involves gradually increasing the concentration of one specific compound, and looking for a rise in peak height. Here, you can identify which peak corresponds to the compound you spiked. You can do this for each alkene, to determine its peak and retention time.

7 0

3 years ago