A chemical reaction occurs when one or more change into one or more new substances called

Given the law of conservation of energy, what happens when a 200°C iron bar is placed in thermal contact with a 30°C block of wo

kozerog [31]

Answer:

The correct answer is A Energy leaves the iron bar and enters the wood until the temperature are equal.

Explanation:

According to the law of conservation of energy or the first law thermodynamics energy neither be created nor destroyed, energy is transferred from one form to another form.

Here iron bar is placed in wood block energy is transferred from iron bar to wood until the temperatures are equal.

7 0

4 years ago

Abbrevation of mass in the si unit

Leno4ka [110]

The SI unit for mass is Kilogram (kg).

3 0

4 years ago

33) 1 e = ........С O 1.6*10^-27 O * 1.6 *10^-19 O 1.66 * 10^-19 o 1.66* 10^-27

Brilliant_brown [7]

Answer

0.16574

Explanation:

because why not

8 0

2 years ago

It takes 60 mL of 0.20 M of sodium hydroxide (NaOH) to neutralize 25 mL of carbonic acid (H2CO3) for the following chemical reac

irina1246 [14]

If It takes 60mL of 0.20M of sodium hydroxide (NaOH) to neutralize 25 mL of carbonic acid ( $H_2CO_3$ ), then the concentration of the carbonic acid is 0.24M

The reaction between NaOH solution and $H_2CO_3$ is written below

$2NaOH + H_2CO_3 \rightarrow Na_2CO_3 + 2H_2O$

Volume of NaOH, $V_B$ = 60 ml

Volume of $H_2CO_3$ , $V_A=25 ml$

Molarity of $H_2CO_3$ , $C_A=?$

Molarity of NaOH, $C_B=0.20M$

Number of moles of $H_2CO_3$ , $n_A=1$

Number of moles of NaOH, $n_B=2$

The mathematical equation for neutralization reaction is:

$\frac{C_AV_A}{C_BV_B} =\frac{n_A}{n_B}$

Substitute $C_B=0.2 M$ , $n_A=1$ , $n_B=2$ , $V_B$ = 60ml, and $V_A=25 ml$ into the equation above in order to solve for $C_A$

$\frac{C_A \times 25}{0.2 \times 60}=\frac{1}{2} \\\\50C_A=12\\\\C_B=\frac{12}{50} \\\\C_B=0.24M$

Therefore, the concentration of the carbonic acid is 0.24M

Learn more here: brainly.com/question/25943090

3 0

2 years ago

When a compound containing cesium ions is heated in a Bunsen burner flame, photons with an energy of 4.30 x 10-19 J are emitted.

inessss [21]

Answer: The wavelength of the flame is 462 nm and color of cesium flame is blue.

Explanation:

To calculate the wavelength, we use Planck's equation, which is:

$E=\frac{hc}{\lambda}$

where,

E = Energy of 1 photon = $4.30\times 10^{-19}J$

h = Planck's constant = $6.625\times 10^{-34}J.s$

c = speed of light = $3\times 10^8m/s$

$\lambda$ = wavelength = ?

Putting values in above equation, we get:

$4.30\times 10^{-19}=\frac{6.625\times 10^{-34}J.s\times 3\times 10^8m/s}{\lambda }\\\\\lambda=\frac{6.625\times 10^{-34}J.s\times 3\times 10^8m/s}{4.30\times 10^{-19}}=4.62\times 10^{-7}m=462nm$

The range of wavelength of blue light lies in range of 500 nm - 435 nm

The calculated wavelength lies in the above range. So, the color of the cesium flame is 462 nm

Hence, the wavelength of the flame is 462 nm and color of cesium flame is blue.

6 0

3 years ago