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3 years ago

Help me get this right no links

Chemistry

1 answer:

ira [324]3 years ago

6 0

Answer:

the rise and fall is the tides.

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Ok this is so weird but like how do you expose fake friends for talking about you? I know they did it but i dont know how to tal

murzikaleks [220]

Answer:

just do it

Explanation:

8 0

3 years ago

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The time necessary for the decay of one- half sample of a radioactive substance is a _____. mass defect daughter half life nucli

Mazyrski [523]

Answer: half life

Explanation: Radioactive decay follows first order kinetics and the time required for the decay of a radioactive material is calculated as follows:

$t=\frac{2.303}{k}\hspace{1mm}log\frac{x}{a}$

t= time required

k= disintegration constant

x= amount of substance left after time t

a= initial amount of substance

when one half of the sample is decayed, one half of the sample remains and t can be represented as $t_{1/2}$

at $t= t_{1/2}$ , $x=\frac{a}{2}$

$t_{1/2}=\frac{2.303}{k}\hspace{1mm}log\frac{a/2}{a}$

$t_{1/2}=\frac{0.693}{k}$

3 0

3 years ago

Read 2 more answers

1 point If the boy is pushing with 50N of force and the static friction resistance is 70N of force, what will happen? *

solniwko [45]

Nothing, he shouldn’t be able to move it. Think about it like this say you try really hard to push something that is 5,000 pounds and you push as hard as you can. Well you can’t move it bc it weighs more than you can push. I’m sure their is a equation you can use to see how much you can push (body weight=force?)

6 0

3 years ago

What is the mass of 2.15 moles of calcium hydroxide, Ca(OH)2?

ch4aika [34]

159.3 g

mol= mass (g)/ molecular weight (g/mol)

3 0

3 years ago

A student heats 10.52 g of sodium hydrogen carbonate in a crucible until the compound completely decomposes to sodium carbonate

saveliy_v [14]

Answer:

$m_{Na_2CO_3}^{theoretical}=6.636gNa_2CO_3$

Explanation:

Hello!

In this case, since the decomposition of sodium hydrogen carbonate is:

$2NaHCO_3(s)\rightarrow Na_2CO_3(s)+H_2O(g)+CO_2(g)$

Thus, since there is a 2:1 mole ratio between the sodium hydrogen carbonate and sodium carbonate, and the molar masses are 84.01 and 105.99 g/mol respectively, we obtain the following theoretical yield:

$m_{Na_2CO_3}^{theoretical}=10.52gNaHCO_3*\frac{1molNaHCO_3}{84.01gNaHCO_3}*\frac{1molNa_2CO_3}{2molNaHCO_3} *\frac{105.99gNa_2CO_3}{1molNa_2CO_3}\\\\ m_{Na_2CO_3}^{theoretical}=6.636gNa_2CO_3$

Best regards!

4 0

2 years ago